A pinch roll and roll shape design method for reducing hot rolling coiling misalignment

Abstract

The present invention discloses a pinch roller and a roller shape design method for reducing hot rolling coiling staggering, comprising a pinch roller body, wherein the roller shape of the pinch roller body is symmetrical about the center line of the roller body, a roller shaft is installed at the axis of the pinch roller body, and the corners on both sides of the pinch roller body are set as chamfered parts for covering the edge range of the plate and strip, and a middle area is set between the chamfered parts on both sides for covering the middle range of the plate and strip. The present invention avoids the wave shape of the strip by the chamfered part, so that the middle area clamps the middle part of the strip with good flatness, thereby improving the uniformity of the force applied by the pinch roller, reducing the deviation of the strip, and designing the length and height of the chamfer of the pinch roller; using the form of a quadratic curve, it is possible to take into account strips of different widths while reducing the wear of the pinch roller, so that the contact length between the pinch roller body and the strip has the ability to adapt to the middle part of the clamped strips of different widths, thereby uniformizing the contact pressure between the pinch roller and the strip and improving the self-maintenance of the roller shape.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical rolling, in particular to a pinch roll and a roll shape design method thereof for reducing hot rolling coiling staggering. Background Art

[0002] Coil shape is a key quality indicator for plate and strip products. Poor coil shape quality will require additional finishing, increasing labor intensity and product costs. As strip products become stronger and thinner, rolling and post-rolling cooling produce noticeable wave shapes, particularly double-sided waves that often occur after laminar cooling. Strips with wave-shaped defects will experience severe deviations when passing through the pinch rollers due to uneven lateral pressure, leading to coiling misalignment. Currently, most plate and strip manufacturers reduce misalignment by reducing the opening of the front guide plate to forcefully clamp the strip. However, this can lead to more serious problems such as scratches on the strip edges, flanging, and even steel piling.

[0003] Roller profile technology is the most direct and active factor in strip shape control. Traditionally, pinch roll profiles have employed a "flat roll + chamfer" approach. However, the chamfer size is often designed based on pinch roll wear, without considering strip wave shape, making it difficult to adapt to the production of various strip widths. Therefore, to address the problem of poor coil shape caused by strip wave shape, further optimization of the pinch roll design is required.

[0004] Therefore, it is necessary to develop a pinch roll and roll shape design method to reduce the staggering of hot rolling coiling. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for designing a pinch roller and its roller shape for reducing the staggering of hot-rolled coiling. The chamfered portion avoids the wave shape of the strip, so that the middle area clamps the middle part of the strip with good flatness, thereby improving the uniformity of the force applied to the pinch roller and reducing the deviation of the strip. The length and height of the chamfer of the pinch roller are designed according to the position and size of the double-sided waves after laminar cooling; the quadratic curve form is used to make the contact length between the pinch roller body and the strip have the ability to adapt to the middle part of the clamped strip of different widths, thereby uniformizing the contact pressure between the pinch roller and the strip to solve the problems raised in the background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A pinch roll for reducing staggered hot rolling coiling, comprising a pinch roll body, the roller shape of the pinch roll body being symmetrical about the center line of the roll body, a roller shaft being mounted at the axis of the pinch roll body, both side corners of the pinch roll body being chamfered for covering the edge range of the plate and strip, and a middle area being provided between the chamfered portions for covering the middle range of the plate and strip;

[0008] The outer edge of the middle area is designed to be convex in arc shape. When the pinch roller body rolls, the middle area is in linear contact with the middle of the upper surface of the strip.

[0009] Preferably, the outer edge of the cross-section plane of the middle region is set as a quadratic curve, the two curves are connected to each other and are axially symmetrically distributed, and the cross-section edge of the chamfered portion is set as a straight line.

[0010] A method for designing a pinch roll profile for reducing hot rolling coiling staggering comprises the following steps:

[0011] S1. Determine the range of the straight chamfer and the middle curve: obtain the roller body length L of the pinch roller body and measure the width l of the edge wave w and the maximum height of the side waves h max , solve the length l of a single chamfer according to the measured value c and the length l of the middle region m ;

[0012] S2. Design the quadratic curve in the middle area: According to the l obtained in S1 m , design the middle curve height h m , and based on l m and h m Calculate the curve coefficient C and deduce the quadratic curve expression for the middle area;

[0013] S3. Design straight chamfer: obtain the maximum height h of the strip edge wave max , design chamfer height h c , and based on h c and l c Calculate the chamfer coefficient a and deduce the expression for straight line chamfer;

[0014] S4. Complete the full roller body roll shape design of the pinch roller body: combine the quadratic curve in the middle area with the straight chamfers on both sides in a coordinate system to construct the full roller body roll shape model of the pinch roller body.

[0015] Preferably, in S1, l c By l w OK, its expression is:

[0016] l c =l w +50mm.

[0017] Preferably, in S1, l m By L and l c Calculated and determined, the expression is:

[0018] l m =L-2l c .

[0019] Preferably, in S2, the quadratic curve expression of the middle region is:

[0020] y m =Cx 2 ,|x|≤0.5Ll c

[0021] In the formula, the curve coefficient C is given by h m and l m OK, its expression is:

[0022]

[0023] Wherein, x is the horizontal coordinate of the roller body with the midpoint of the pinch roller body as the origin;

[0024] y m It is the roller shape ordinate corresponding to the middle area of ​​the pinch roller body.

[0025] Preferably, the h m The value range is set to 0.1-0.3mm, and l m With h m There is a positive correlation.

[0026] Preferably, in S3, the expression for the straight line chamfer is:

[0027] y c =h m +a(|x|-0.5l m ),0.5Ll c <|x|<0.5L

[0028] In the formula, the chamfer coefficient a is given by h c and l c OK, its expression is:

[0029]

[0030] h c =k·h max

[0031] Wherein, k is the correction coefficient of straight chamfer;

[0032] y c The vertical coordinate of the roller shape corresponding to the horizontal coordinate of the roller body of the linear chamfer.

[0033] Preferably, k is 0.1, and h c ≤4mm.

[0034] Preferably, the roller shape model of the entire roller body of the pinch roller body is expressed as:

[0035]

[0036] The present invention has the following beneficial effects:

[0037] 1. The chamfered portion avoids the strip wave shape, allowing the middle area to clamp the middle part of the strip with good flatness, thereby improving the uniformity of the force applied to the pinch rollers and reducing strip deviation. The length and height of the pinch roller chamfer are designed based on the position and size of the double-sided waves after laminar cooling. The quadratic curve form can take into account strips of different widths while reducing the wear of the pinch rollers. The contact length between the pinch roller body and the strip and the middle part of the clamped strips of different widths have the ability to adapt to each other, thereby uniformizing the contact pressure between the pinch rollers and the strip and improving the self-maintenance of the roller shape.

[0038] 2. By determining the range of the straight chamfer and the middle curve, designing the quadratic curve in the middle area, and designing the straight chamfer until the full roller shape design of the pinch roller body is completed, the design scheme is simple and convenient. This scheme provides an actual calculation method for the roller shape of the pinch roller, which can control the accuracy of the roller shape, facilitate its processing and use, improve the working stability of the pinch roller, and extend the service life of the pinch roller.

[0039] 3. The pinch rollers are produced by the roller design method provided in this solution and applied to the production line. In actual application, the yield rate of the hot rolling production line is improved and the coil defect rate is significantly reduced, which not only reduces the labor intensity of workers but also creates good production benefits for the production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A three-dimensional diagram of the combined structure of the pinch roller body and the roller shaft provided by the present invention;

[0041] Figure 2 A cross-sectional view of the combined structure of the pinch roller body and the roller shaft provided by the present invention;

[0042] Figure 3 A flow chart of the pinch roller profile design method provided by the present invention;

[0043] Figure 4 This is a geometric diagram of the shape of the pinch roller in the embodiment provided by the present invention.

[0044] Among them are:

[0045] Pinch roller body-1; roller shaft-2; chamfered portion-11; middle area-12. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and specific preferred embodiments.

[0047] In the description of the present invention, it should be understood that the terms "left side," "right side," "upper," "lower," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Terms such as "first" and "second" do not indicate the importance of components and therefore should not be construed as limitations on the present invention. The specific dimensions used in this embodiment are intended only to illustrate the technical solution and do not limit the scope of protection of the present invention.

[0048] like Figure 1-2 A pinch roll for reducing staggered hot rolling coiling is shown, comprising a pinch roll body 1. The pinch roll body 1 has a roll shape symmetrical about the roll body centerline. A roll shaft 2 is mounted at the axis of the pinch roll body 1. Both side corners of the pinch roll body 1 are provided with chamfered portions 11 for covering the edge range of the plate and strip and avoiding the strip's wave shape. A middle region 12 is provided between the chamfered portions 11 for covering the middle range of the plate and strip and clamping the middle portion of the strip with good flatness as much as possible, thereby improving the uniformity of the force applied to the pinch roll and reducing strip deviation.

[0049] The outer edge of the middle region 12 is designed to be convex in arc shape. When the pinch roller body 1 rolls, the middle region 12 is in linear contact with the middle of the upper surface of the strip. Specifically, the outer edge of the cross-sectional plane of the middle region 12 is set as a quadratic curve. The two curves are connected to each other and are axially symmetrical. The cross-sectional edge of the chamfered portion 11 is set as a straight line.

[0050] The contact length between the pinch roller body 1 and the strip steel is adaptive to the middle part of the clamped strip steel of different widths, thereby uniformizing the contact pressure between the pinch roller and the strip steel and improving the self-maintenance of the roller shape.

[0051] like Figure 3 A method for designing a pinch roll profile to reduce hot rolling coiling staggering is shown, comprising the following steps:

[0052] S1. Determine the range of the straight chamfer and the middle curve: obtain the roller length L of the pinch roller body 1 and measure the width l of the edge wave w and the maximum height of the side waves h max , solve the length l of a single chamfered portion 11 based on the measured value c and the length l of the middle region 12 m ;

[0053] Specifically:

[0054] The length l of a single chamfered portion 11 c The width of the plate edge wave l w OK, its expression is:

[0055] lc =l w +50mm

[0056] The length l of the middle region 12 m The roller body length L of the pinch roller body 1 and the length l of the single chamfered portion 11 are c Calculated and determined, the expression is:

[0057] l m =L-2l c

[0058] S2. Design the quadratic curve of the middle region 12: Based on the length l of the middle region 12 obtained in S1 m , design the middle curve height h m , and based on the length l of the middle region 12 m and the middle curve height h m Calculate the curve coefficient C and deduce the quadratic curve expression of the middle area 12;

[0059] Specifically:

[0060] The quadratic curve expression of the middle region 12 is:

[0061] y m =Cx 2 ,|x|≤0.5Ll c

[0062] In the formula, the curve coefficient C is determined by the middle curve height h m and the length l of the middle region 12 m OK, its expression is:

[0063]

[0064] Wherein, x is the horizontal coordinate of the roller body with the midpoint of the pinch roller body 1 as the origin;

[0065] y m is the roller shape ordinate corresponding to the middle region 12 of the pinch roller body 1;

[0066] S3. Design straight chamfer: obtain the maximum height h of the strip edge wave max , design chamfer height h c , and based on the chamfer height h c and the length l of the single chamfered portion 11 c Calculate the chamfer coefficient a and deduce the expression for straight line chamfer;

[0067] Specifically:

[0068] The expression for straight line chamfer is:

[0069] yc =h m +α(|x|-0.5l m ),0.5Ll c <|x|<0.5L

[0070] In the formula, the chamfer coefficient a is determined by the chamfer height h c and the length l of the single chamfered portion 11 c OK, its expression is:

[0071]

[0072] h c =k·h max

[0073] Among them, k is the correction coefficient of the straight chamfer, k is 0.1, and h c ≤4mm;

[0074] y c The vertical coordinate of the roller shape corresponding to the horizontal coordinate of the roller body is the linear chamfer;

[0075] S4. Complete the roll shape design of the entire roller body of the pinch roller body 1: Combine the quadratic curve of the middle area 12 with the linear chamfers on both sides in a coordinate system to construct a roll shape model of the entire roller body of the pinch roller body 1; its expression is:

[0076]

[0077] As an embodiment of the present invention:

[0078] The factory has a 1450mm hot rolling production line, which uses a pinch roll with a roller length of L = 1500mm and processes a normal rolled strip with a width of 1250mm. The actual width of the double-sided wave measured at the production site is l w =350mm, height h max =20mm.

[0079] This embodiment is implemented according to a roll shape design method for pinch rolls that reduces hot rolling coiling misalignment.

[0080] First, determine the size of the pinch roller middle area 12 and the chamfered portion 11;

[0081] The single-side chamfer length l of the pinch roller body 1 c =l w +50=400mm, then the length of the middle area 12 of the pinch roller is l m =1500-2×l c =700mm;

[0082] Chamfer height h c =0.1*hmax =2mm;

[0083] Next, the quadratic curve of the middle region 12 is designed, and the equation is expressed as follows:

[0084] y m =Cx 2 ,|x|≤350

[0085] The solution process of coefficient C is:

[0086]

[0087] Take h m is 0.1mm, and the known parameters are substituted into:

[0088] C = 8.163E-7;

[0089] Next, the linear chamfer of the pinch roller body 1 is designed, and the equation is:

[0090] y c =h m +a(|x|-0.5l m ),350<|x|≤750

[0091] Substituting the known parameters into the expression, we can get the chamfer coefficient a=0.005;

[0092] Finally, the roller shape ordinate y(x) of the entire roller body of the pinch roller is obtained as:

[0093]

[0094] The pinch roller shape design is completed here, and the roller shape is shown as follows Figure 4 As shown;

[0095] According to the correspondence between the horizontal coordinate and the vertical coordinate of the pinch roller shape, the pinch roller body 1 is processed and installed for use. After the production line uses the pinch roller with this roller shape, the yield rate of the hot rolling production line is increased from the original 98.49% to 98.60%, and the poor coil shape causes the finishing material to be reduced from 1,160 tons / month to 420 tons / month; after actual production verification, the designed roller shape structure effectively overcomes the defects of the existing technology.

[0096] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments may be made without departing from the principles and spirit of the present invention, and these changes and modifications still fall within the scope of protection of the present invention.

Claims

1. A method for designing the roller shape of a pinch roller for reducing staggered layers in hot rolling coiling, the pinch roller comprising a pinch roller body (1), the roller shape of the pinch roller body (1) being symmetrical about the center line of the roller body, a roller shaft (2) being installed at the axis of the pinch roller body (1), both side corners of the pinch roller body (1) being configured as chamfered portions (11) for covering the edge range of the plate and strip, and a middle region (12) being configured between the chamfered portions (11) on both sides for covering the middle range of the plate and strip; The outer edge of the middle region (12) is designed to be convex in arc shape, and when the pinch roller body (1) rolls, the middle region (12) is in linear contact with the middle of the upper surface of the strip; The outer edge of the cross-section plane of the middle region (12) is set as a quadratic curve, the two curves are connected to each other and are axially symmetrically distributed, and the cross-section edge of the chamfered portion (11) is set as a straight line; Its characteristics are: The roll shape design method includes the following steps: S1. Determine the range of the straight chamfer and the middle curve: obtain the roller length L of the pinch roller body (1) and measure the width l of the edge wave w and the maximum height of the side wave h max , solve the length l of a single chamfered portion (11) based on the measured value c and the length l of the middle region (12) m ; S2. Design the quadratic curve of the middle area (12): According to the l obtained in S1 m , design the middle curve height h m , and based on l m and h m Calculate the curve coefficient C and deduce the quadratic curve expression of the middle area (12); S3. Design straight chamfer: obtain the maximum height h of the strip edge wave max , design chamfer height h c , and based on h c and l c Calculate the chamfer coefficient a and deduce the expression for straight line chamfer; S4. Complete the full roller body roll shape design of the pinch roller body (1): combine the quadratic curve of the middle area (12) and the straight line chamfers on both sides in a coordinate system to construct the full roller body roll shape model of the pinch roller body (1).

2. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 1, characterized in that: In S1, l c By l w OK, its expression is: L c =l w +50mm.

3. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 2, characterized in that: In S1, l m By L and l c Calculated and determined, the expression is: l m ＝L-2l c 。 4. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 1, characterized in that: In S2, the quadratic curve expression of the middle region (12) is: y m =Cx 2 ,|x|≤0.5L-l c In the formula, the curve coefficient C is given by h m and l m OK, its expression is: Wherein, x is the horizontal coordinate of the roller body with the midpoint of the pinch roller body (1) as the origin; y m It is the roller shape ordinate corresponding to the middle area (12) of the pinch roller body (1).

5. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 4, characterized in that: The h m The value range is set to 0.1-0.3mm, and l m With h m There is a positive correlation.

6. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 1, characterized in that: In S3, the expression for straight line chamfer is: y c =h m +a(|x|-0.5l m ),0.5L-l c <|x|<0.5L In the formula, the chamfer coefficient a is given by h c and l c OK, its expression is: h c =k·h max Wherein, k is the correction coefficient of straight chamfer; y c The vertical coordinate of the roller shape corresponding to the horizontal coordinate of the roller body of the linear chamfer.

7. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 6, characterized in that: k is set to 0.1, and h c ≤4mm.

8. The method for designing a pinch roll profile for reducing hot rolling coiling staggering according to claim 1, characterized in that: In S4, the expression of the full roller body roll shape model of the pinch roller body (1) is:

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