Method for controlling the diameter of intermediate billet steel coils in hot rolling mills

Abstract

This invention relates to a method for controlling the diameter of intermediate billet steel coils in a hot-rolled coil box, belonging to the technical field of metal strip production using non-rolling methods. The method first determines the standard base circle radius range and standard coil diameter range of the intermediate billet steel coil based on the specific hot-rolled coil box. Then, by setting the longitudinal axis sectional plane of the hot-rolled coil box and the intermediate billet steel coil along the same running direction as a coordinate plane, several hinge points of the hot-rolled coil box that generate movement, the center of the intermediate billet steel coil, and the center of its idler rollers are projected onto this coordinate plane to establish a Cartesian coordinate system. This allows for real-time tracking and calculation of the coordinates of point E, the hinge point between the insert arm and the shovel head, within this coordinate plane. Simultaneously, the moment when the shovel head approaches the intermediate billet steel coil and generates a trigger signal is introduced, and the coordinates of point E at that moment are read and calculated. Finally, the real-time coil diameter of the intermediate billet steel coil is calculated. The real-time coil diameter is then compared with the standard coil diameter range, and the coil diameter is controlled by adjusting the bending roll gap.

Description

Technical Field

[0001] This invention relates to a method for calculating and controlling the diameter of intermediate billet steel coils in a hot rolling mill, belonging to the technical field of producing metal strips using non-rolling methods. Background Technology

[0002] The main function of the hot coil box is to coil the rough-rolled intermediate billet without a mandrel, then uncoil it to transform the tail end into the head end and the lower surface into the upper surface, before sending it to the finishing mill for rolling. Its biggest advantage is that it eliminates the temperature difference between the head and tail, ensuring product quality, improving the stability of thin-gauge and high-deformation-resistance products, mitigating the impact of secondary iron oxide scale on surface quality, and improving descaling efficiency. The coil shape quality of the intermediate billet is a key indicator for inspecting the hot coil box. The coil shape quality refers to the coil diameter (outer radius of the steel coil) meeting the standard requirements and remaining consistent (i.e., good roundness of the coil). High coil shape quality results in less impact on the equipment in the coiling area; conversely, if the actual coil diameter differs too much from the standard requirement (the coil is too loose or too tight, usually too loose), it will affect the timing of the tail setting, uncoiling, and subsequent tail-flattening pin operations, thus impacting strip rolling production. Generally, the size of the eye radius when the intermediate billet is coiled is a key factor in the final coil diameter. This eye radius is usually called the base circle radius. Based on production experience, different production lines have their own optimal standard base circle radius range for the hot-rolling box. The coil diameter range formed within this optimal standard base circle radius range is the optimal standard coil diameter range. If the coil diameter of the intermediate billet formed by the hot-rolling box in actual production exceeds the optimal standard coil diameter range, it is necessary to adjust the coil diameter by adjusting the gap between the bending rollers of the hot-rolling box.

[0003] Currently known methods for acquiring and controlling the diameter of rolled steel coils involve photographing the formed steel coil with an installed camera and then using a computer image processing system to obtain the diameter of the rolled steel coil in the hot rolling box. However, this method is expensive and has a high error rate. Apart from this, no other technologies related to acquiring and controlling the diameter of rolled steel coils in the hot rolling box have been reported. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to acquire and control the actual diameter of the steel coils rolled in the hot rolling box in real time.

[0005] The technical solution proposed by this invention to solve the above-mentioned technical problems is: a method for controlling the diameter of intermediate billet steel coils in a hot-rolling box, the hot-rolling box including a large swing arm hinged at one end to a gate base, an insertion arm hinged at one end to the other end of the large swing arm, and a shovel head hinged to the other end of the insertion arm. A hydraulic cylinder is installed on the large swing arm 2, the piston rod fork of the hydraulic cylinder is hinged to one end of the insertion arm, an angle sensor is provided at one end of the large swing arm, a displacement sensor is provided on the hydraulic cylinder, and two support rollers A and B are provided at the bottom of the intermediate billet steel coil to support the intermediate billet steel coil; the following steps are performed: 1) According to the specific hot-rolling box, determine the standard base circle radius range and the standard steel coil radius range (r1, r2) of the intermediate billet steel coil;

[0006] 2) Set the longitudinal axis sectional plane where the hot-rolled coil box and the intermediate billet coil are in the same running direction as the coordinate plane.

[0007] Projecting the hinge point between the insertion arm and the large swing arm of the hot roll box into the coordinate plane forms point D.

[0008] Projecting the hinge point between the large swing arm of the hot roll box and the archway base into the coordinate plane forms point O.

[0009] Projecting the hinge point between the insertion arm of the hot roll box and the shovel head onto the coordinate plane forms point E.

[0010] Projecting the center of the intermediate billet coil onto the coordinate plane forms point Q.

[0011] Projecting the centers of rollers A and B onto the coordinate plane will form points A and B, respectively.

[0012] 3) Establish a Cartesian coordinate system in the coordinate plane with point O as the origin. Set the cylinder to be in full stroke state. At this time, points O, D, and E form a fixed triangle △ODE. The side lengths OE, OD, and ED of triangle △ODE are known fixed values. The coordinate values ​​of points A and B are known fixed coordinate values, denoted as (X... A Y A ) and (X B Y B The coordinates of point Q are denoted as (X...). Q Y Q The radii of rollers A and B are known fixed values ​​r0, and the angle ∠DOE of triangle △ODE is known fixed value β1. Let the angle between line segment OD and the vertical coordinate be β and be read in real time by the angle sensor.

[0013] 4) As the insert arm and shovel head move closer to the intermediate billet coil, when the shovel head contacts the intermediate billet coil and presses down to generate a trigger signal, calculate and read the coordinate value (X) of point E at this moment according to the following formulas (1)-(2). E Y E ),

[0014] X E =OE*cos(90-β-β1), (1)

[0015] Y E =OE*sin(90-β-β1) (2)

[0016] 5) Form a circle with points E, A, and B at this point. Calculate the radius R of the circle using the coordinates of points E, A, and B according to formulas (3)-(5).

[0017] R 2 =(X Q -X E ) 2 +(Y Q -Y E ) 2 (3)

[0018] R 2 =(X Q -X A ) 2 +(Y Q -Y A ) 2 (4)

[0019] R 2 =(X Q -X B ) 2 +(Y Q -Y B ) 2 (5)

[0020] 6) The difference between R and the radii r0 of rollers A and B is taken as the actual radius R of the intermediate billet coil at this time. S Then, the actual radius R S Compared with the standard steel coil radius range (r1, r2), if R S If R > r2, then adjust the bending roller gap of the hot rolling box to be smaller. S If r1 < r1, then the bending roller gap of the hot rolling box is increased; if r1 ≤ R S If r2 ≤ r2, then no adjustment is needed.

[0021] The beneficial effects of this invention are as follows: First, based on the specific hot coil box, the standard base circle radius range and standard coil diameter range of the intermediate billet steel coil are determined. Then, by setting the longitudinal axis sectional plane of the hot coil box and the intermediate billet steel coil along the same running direction as the coordinate plane, the several hinge points of the hot coil box that generate movement, the center of the intermediate billet steel coil, and the center of its idler roller are projected into this coordinate plane and a plane rectangular coordinate system is established. Thus, in this coordinate plane, the coordinate value of point E of the moving hinge point (the hinge point between the insertion arm and the shovel head) is tracked and calculated in real time. At the same time, the moment when the shovel head moves close to the intermediate billet steel coil and generates a trigger signal is introduced, and the coordinate value of point E at that moment is read and calculated. Thus, the real-time coil diameter of the intermediate billet steel coil is finally calculated. Finally, the obtained real-time coil diameter is compared with the standard coil diameter range, thereby controlling the coil diameter of the intermediate billet steel coil by adjusting and controlling the bending roll gap of the hot coil box. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the hot roll box.

[0024] Figure 2 yes Figure 1 When the intermediate billet is coiled in the hot coil box, along Figure 1 A cross-sectional view along the HH direction.

[0025] Figure 3 yes Figure 2 A cross-sectional view of the shovel head moving close to the intermediate billet coil in the medium-heat coil box. Detailed Implementation

[0026] Example

[0027] This embodiment uses a hot-rolling box from a certain 1422 production line as an example. The thickness h of a certain intermediate billet is 40mm, and the total length L of the intermediate billet is 50000mm. Figure 1 and Figure 2 As shown, the hot-rolling box includes a large swing arm 2 hinged at one end to a gate base (not shown in the figure), an insertion arm 3 with one end hinged to the other end of the large swing arm 2, and a shovel head 4 hinged to the other end of the insertion arm 3. A hydraulic cylinder 1 is mounted on the large swing arm 2, and the piston rod fork of the hydraulic cylinder 1 is hinged to one end of the insertion arm 3. An angle sensor 5 is provided at one end of the large swing arm 2, and a displacement sensor 7 is provided on the hydraulic cylinder 1. After being bent and formed by the hot-rolling box, the steel coil 9 is as follows: Figure 2 It is spiral-shaped.

[0028] This embodiment describes a method for controlling the diameter of intermediate billet steel coils in a hot-rolling box, which involves the following steps:

[0029] 1) Based on the hot-rolling box of production line 1422, the standard base circle radius r of the intermediate billet steel coil is determined to be within the range of (250mm, 300mm), and the standard steel coil radius is within the range of (r1 = 846mm, r2 = 862mm) (i.e., 846mm~862mm). The standard steel coil radius is determined based on the determined base circle radius r range (250mm, 300mm) and the total length of the intermediate billet L = 50000mm, using the helical formula L = 2πnr + πn 2 h is calculated using a known calculation method, which will not be elaborated upon in this embodiment.

[0030] 2) Set the longitudinal axis sectional plane of the hot-rolled coil box and the intermediate billet coil along the same running direction as the coordinate plane, such as... Figure 2 and Figure 3 As shown;

[0031] Project the hinge point between the insertion arm 3 and the large swing arm 2 of the hot roll box onto the coordinate plane to form point D.

[0032] Project the hinge point between the large swing arm 2 of the hot roll box and the archway base onto the coordinate plane to form point O.

[0033] Project the hinge point between the insertion arm 3 of the hot roll box and the shovel head 4 onto the coordinate plane to form point E.

[0034] Project the hinge point between the piston rod fork of the hot roll box cylinder 1 and the insertion arm 3 onto the coordinate plane to form point F.

[0035] Project the center of the intermediate billet steel coil 9 onto the coordinate plane to form point Q.

[0036] Project the centers of the two A and B rollers at the bottom of the intermediate billet coil 9 onto the coordinate plane to form points A and B respectively.

[0037] 3) Establish a Cartesian coordinate system with point O as the origin in the coordinate plane. Set the cylinder 1 to be in full stroke state. At this time, the three points O, D, and E form a fixed triangle △ODE. The side lengths OE, OD, and ED of triangle △ODE are known fixed values. In this embodiment, OE = 2378.37mm, OD = 2068mm, and ED = 1919.09mm. The coordinate values ​​of points A and B are known fixed coordinate values, denoted as (X... A Y A ) and (X B Y B In this embodiment, the coordinates of point A are (X... A =431.54mm,Y A = -3266.34mm), the coordinates of point B are (X B =1227.41mm,Y B = -3335.74mm);

[0038] The radii of rollers A and B are known fixed values ​​r0. In this embodiment, the radii of rollers A and B are both 200mm.

[0039] The angle ∠DOE of triangle △ODE is a known fixed value β1. In this embodiment, β1 = 50.55 degrees; let β be the angle between the OD line segment and the vertical coordinate.

[0040] 4) As the insert arm 3 and the shovel head 4 move closer to the intermediate billet steel coil 9, the angle sensor 5 reads β in real time. When the shovel head 4 contacts the intermediate billet steel coil 9 and presses down, the piston rod of the hydraulic cylinder 1 retracts, triggering the displacement sensor 7 to generate a trigger signal. At this moment, β = 81.69. The coordinate value of point E at this moment is calculated and read according to the following formulas (1)-(2). E Y E ),

[0041] X E =OE*cos(90-β-β1), (1)

[0042] Y E =OE*sin(90-β-β1) (2)

[0043] In this embodiment, X E =OE*cos(90-β-β1)=2378.37*cos(90-50.55-81.69)=1760.79mm, Y E =OE*sin(90-β-β1)=2378.37*sin(90-50.55-81.69)=-1598.83mm, therefore, the coordinates of point E at this time are (1760.79, -1598.83).

[0044] 5) Form a circle with points E, A, and B at this point. Calculate the radius R of the circle using the coordinates of points E, A, and B according to formulas (3)-(5).

[0045] R 2 =(X Q -X E ) 2 +(Y Q -Y E ) 2 (3)

[0046] R 2 =(X Q -X A ) 2 +(Y Q -Y A ) 2 (4)

[0047] R 2 =(X Q -X B ) 2 +(Y Q -Y B ) 2 (5)

[0048] In this embodiment,

[0049] R 2 =(X Q -1760.79) 2 +(Y Q +1598.83) 2 (3)

[0050] R 2 =(X Q -431.54) 2 +(Y Q +3266.34) 2 (4)

[0051] R 2 =(X Q -1227.41) 2 +(Y Q +3335.74) 2 (5)

[0052] (3)-(4) yields (X) Q -1760.79) 2 +(Y Q +1598.83) 2 -(X Q -431.54) 2 -(Y Q +3266.34) 2 =0 (6)

[0053] (3)-(5) yields (X) Q -1760.79) 2 +(Y Q +1598.83) 2 -(X Q -1227.41) 2 -(Y Q +3335.74) 2 =0 (7)

[0054] Solving equation (6) yields equation (8) as follows:

[0055] X Q 2 -2*1760.79*XQ +1760.79 2 +Y Q 2 +2*1598.83Y Q +1598.83 2 -X Q 2 +2*431.54*X Q -431.54 2 -Y Q 2 -2*3266.34Y Q -3266.34 2 =0

[0056] (2*431.54-2*1760.79)X Q +(2*1598.83-2*3266.34)Y Q +1598.83 2 +1760.79 2 -431.54 2 -3266.34 2 =0

[0057] (-2658.5)X Q +(-3335.02)Y Q -5198564.9742=0 (8)

[0058] Solving equation (7) yields equation (9) as follows:

[0059] X Q 2 -2*1760.79*X Q +1760.79 2 +Y Q 2 +2*1598.83Y Q +1598.83 2 -X Q 2 +2*1227.41*X Q -1227.41 2 -Y Q 2 -2*3335.74Y Q -3335.74 2 =0

[0060] (2*1227.41-2*1760.79)X Q +(2*1598.83-2*3335.74)Y Q -3335.742 +1760.79 2 +1598.83 2 -1227.41 2 =0

[0061] (-1066.76)X Q +(-3473.82)Y Q -6977057.8627=0 (9)

[0062] Find the two linear equations in equations (8) and (9), and solve them to obtain X. Q =917.615, Y Q =-2290.25,

[0063] The solution X Q Y Q Substitute into equation (6)

[0064] R 2 = (917.615 - 1760.79) 2 +(-2290.25+1598.83) 2

[0065] Calculations show that R≈1091mm.

[0066] 6) The difference between R and the radii r0 of rollers A and B is taken as the actual coil radius R of the intermediate billet at this time. S Then, the actual steel coil radius R S Compared with the standard steel coil radius range (r1, r2), if R S If R > r2, then adjust the bending roller gap of the hot rolling box to be smaller. S If r1 < r1, then the bending roller gap of the hot rolling box is increased; if r1 ≤ R S ≤r2, i.e., the actual radius R of the steel coil S If the radius falls within the standard steel coil radius range, no adjustment is needed.

[0067] In this embodiment, R S =1091-200=891mm. Since 891>862, the bending roller gap of the hot rolling box needs to be adjusted to be smaller. Specifically, the offset value of the roller gap is reset. This is a known technology and will not be described in detail in this embodiment.

[0068] The following points need to be explained:

[0069] 1. In step 3) of the above embodiment, setting the cylinder 1 to the full stroke state is to keep the triangle △ODE in a fixed state so that the side lengths OE, OD and ED of the triangle △ODE and the included angle ∠DOE are fixed values ​​β1.

[0070] 2. In step 4) of the above embodiment, the purpose of triggering the displacement sensor 7 by retracting the piston rod of cylinder 1 is to determine the coordinate value of point E at a specific triggering moment (when the included angle ∠DOE begins to change). Otherwise, during the process of the insertion arm 3 and the shovel head 4 moving closer to the intermediate billet steel coil 9, the angle sensor 5 will read many β values ​​(the angle between the OD line segment and the vertical coordinate) and point E coordinate values ​​in real time. However, only the point E at the moment when the piston rod of cylinder 1 retracts and triggers the displacement sensor 7 can determine that the shovel head 4 has contacted the intermediate billet steel coil. Therefore, the point E coordinate value at this moment is taken. Obviously, in addition to taking the point E coordinate value at the moment when the piston rod of cylinder 1 retracts and triggers the displacement sensor 7, a flow sensor can also be installed on the rodless chamber hydraulic circuit of cylinder 1, or an angle encoder can be installed at point D (the hinge point between the insertion arm 3 and the large swing arm 2) to detect when ∠DOE (β1) changes and trigger the reading of the calculated point E coordinate value.

[0071] 3. Since there are certain errors in the length and thickness of the strip, and the outer ring of the spiral steel coil 9 is only an approximate circular curve, the calculated value of the standard coil diameter in step 1) of the above embodiment is an approximate standard coil diameter.

[0072] The above description is only a preferred embodiment of the present invention, but the present invention is not limited thereto. All equivalent substitutions or modifications made to the concepts and technical solutions of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for controlling the diameter of intermediate billet steel coils in a hot-rolled coil box, the hot-rolled coil box comprising a large swing arm hinged at one end to a gate base, an insertion arm hinged at one end to the other end of the large swing arm, and a shovel head hinged to the other end of the insertion arm; a hydraulic cylinder is mounted on the large swing arm, the piston rod fork of the hydraulic cylinder is hinged to one end of the insertion arm; an angle sensor is provided at one end of the large swing arm; a displacement sensor is provided on the hydraulic cylinder; and two support rollers, A roller and B roller, are provided at the bottom of the intermediate billet steel coil to support it; characterized in that... Perform the following steps: 1) Determine the standard base circle radius range and standard coil radius range (r1, r2) of the intermediate billet steel coil based on the specific hot rolling box. 2) Set the longitudinal axis sectional plane where the hot-rolled coil box and the intermediate billet coil are in the same running direction as the coordinate plane. Projecting the hinge point between the insertion arm and the large swing arm of the hot roll box into the coordinate plane forms point D. Projecting the hinge point between the large swing arm of the hot roll box and the archway base into the coordinate plane forms point O. Projecting the hinge point between the insertion arm of the hot roll box and the shovel head onto the coordinate plane forms point E. Projecting the center of the intermediate billet coil onto the coordinate plane forms point Q. Projecting the centers of rollers A and B onto the coordinate plane will form points A and B, respectively. 3) Establish a Cartesian coordinate system in the coordinate plane with point O as the origin. Set the cylinder to be in full stroke state. At this time, points O, D, and E form a fixed triangle △ODE. The side lengths OE, OD, and ED of triangle △ODE are known fixed values. The coordinate values ​​of points A and B are known fixed coordinate values, denoted as (X... A Y A ) and (X B Y B The coordinates of point Q are denoted as (X...). Q Y Q The radii of rollers A and B are known fixed values ​​r0, and the angle ∠DOE of triangle △ODE is known fixed value β1. Let the angle between line segment OD and the vertical coordinate be β and be read in real time by the angle sensor. 4) As the insert arm and the shovel head move closer to the intermediate billet steel coil, when the shovel head contacts the intermediate billet steel coil and presses down to generate a trigger signal, calculate and read the coordinate value (XE, YE) of point E at this moment according to the following formula (1)-(2). X E =OE*cos(90-β-β1), (1) Y E =OE*sin(90-β-β1) (2) 5) Form a circle with points E, A, and B at this point. Calculate the radius R of the circle using the coordinates of points E, A, and B according to the following formulas (3)-(5). R²=(X Q -X E )²+(Y Q -Y E )² (3) R²=(X Q -X A )²+(Y Q -Y A )² (4) R²=(X Q -X B )²+(Y Q -Y B )² (5) 6) Subtract the radius r0 of roller A or roller B from R to obtain the actual coil radius RS of the intermediate billet at this time; then compare the actual coil radius RS with the standard coil radius range (r1, r2). If RS > r2, adjust the bending roll gap of the hot coil box to be smaller; if RS < r1, adjust the bending roll gap of the hot coil box to be larger; if r1 ≤ RS ≤ r2, do not adjust.

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