CN101714177A - Crossing angle and roll bending force reduction based roll shape design method of work roll of PC rolling mill - Google Patents

Abstract

The invention provides a crossing angle and roll bending force reduction based roll shape design method of a work roll of a PC rolling mill, aiming at the rolling characteristics of the PC rolling mill. The roll shape design method comprises the following steps of: (a) collecting equipment parameters and process parameters of the PC rolling mill; (b) collecting rolling process parameters of typical band steel; (c) setting a curve equation of the work roll; (d) optimally computing curve parameters of a roll shape; and (e) substituting the curve parameters of the roll shape into the roll shape curve equation of the work roll so as to obtain an optimized roll shape curve equation of the work roll. The invention enhances the stability of the PC rolling mill because a roll shape curve of the work roll reduces the crossing angle and the roll bending force, prolongs the service life of the work roll, enhances the convexity control capacity of the PC rolling mill, not only ensures the quality requirement of a profile shape, but also meets the requirement for industrial application precision, and can also be used for the roll shape curve design of the work roll of any rack according to actual field situation.

Description

Based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force

Technical field

The present invention relates to a kind of PC milling train designing technique, particularly a kind of based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force.

Background technology

In commercial production, the PC milling train has obtained using widely and promoting in hot rolling and cold-strip steel field with its outstanding plate shape and plate convexity control ability.The characteristics of PC milling train are that top and bottom rolls intersects in pairs, intersect just because of existing between the roll, can produce bigger axial force in the operation of rolling, and along with the increase of intersecting angle, axial force increases thereupon, and this becomes more complicated with regard to the designing requirement that makes rolling machine system.Under the high-speed rolling situation, the PC milling train is owing to the existence of the angle of the crossing, and the stability of milling train is lower than the normal four-roller milling train, the quality of confinement plate carries product and Rolling Production efficient.Because the existence of bending roller force can be quickened the working roll roll surface wear, reduce the serviceable life of working roll and bearing seat thereof in addition, shorten the roll change cycle, increase the workload and the expense of equipment operation maintenance.Therefore, how improving working roll serviceable life, effectively reduce the angle of the crossing and bending roller force, guarantee that plate shape is good, is the emphasis and the difficult point of PC milling train operation technique.

Summary of the invention

The object of the present invention is to provide based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force, make the PC milling train when rolling, can reduce the angle of the crossing and bending roller force, improve the strip crown control ability of PC milling train, not only guarantee the quality requirements of plate shape, and can reach the requirement of commercial Application precision.

To achieve these goals, the present invention has adopted following technical scheme: the PC operation roll of mill roll design method based on reducing the angle of the crossing and bending roller force may further comprise the steps:

(a) collect PC milling equipment parameter and technological parameter:

Comprise working roll barrel length L _w, barrel diameter D _w, roll neck diameter D _Wj, original convexity curve, roller cylinder distance L _Wf, bending roller force F _w, elastic modulus E _w, Poisson ratio v _w, the stiffness K of monolithic support stressed member beyond the roller system _g, maximum bending roller force F _Wmax

(b) collect the rolling technological parameter that the typical case is with steel:

Band steel supplied materials width B, thickness h, elastic modulus E, Poisson ratio v, rolling temperature T, resistance of deformation σ _s, speed of rolls V _R, front and back mean tension σ ₁, σ ₀, angle of the crossing θ, bending roller force F _w

(c) with C _2iBe roller curve parameter and optimization variable, the curvilinear equation of setting working roll is:

$D_w\left(y\right)=D_w-\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{C}_{2i}{\left(\frac{2y}{L_w}\right)}^{2i}$

In the formula:

D _w(y)-the roller curve distribution value of working roll;

Y-is apart from the distance at working roll middle part;

C _2i-roller curve characteristic coefficient;

(d) computation optimization goes out the roller curve parameter, may further comprise the steps:

D1) given initial curve parameters C _2i

D2) the best angle of the crossing θ of calculating ideal format product ₀With best bending roller force F _W0

D3) calculate roll shape objective function of optimization design function G (X);

D4) judge whether the Powell condition is set up,, adjust the roller curve parameter, forward steps d 2 to if be false), if set up, finish to calculate, export optimum roller curve parameter;

(e) with the roller curve equation of above-mentioned roller curve parameter substitution working roll, the working roller curve equation after being optimized;

Steps d 2) the best angle of the crossing θ described in ₀With best bending roller force F _W0Find the solution and comprise the following step of carrying out by computer system:

D21) set initial bending roller force F _W0, the calculating step delta F of given bending roller force _w, maximum angle of the crossing θ _Max, upper spider angle of the crossing θ ^*, initial angle of the crossing θ ₀, the calculating step delta θ of the given angle of the crossing, plate shape objective function initial value B ₀=1.0 * 10 ¹⁰, and get calculation times C _n=1;

D22) given angle of the crossing θ=Δ θ * (C _n-1);

D23) judge θ 〉=θ _MaxWhether set up,, forward steps d 29 to) if set up;

D24) calculate corresponding band forward pull cross direction profiles value σ _1i

D25) value of calculating ejecting plate shape objective function B (X);

D26) judge B (X)≤B ₀Whether set up,, then make B if set up ₀=B (X), θ ₀=θ, F _W0=F _w

D27) order: C _n=C _n+ 1, forward steps d 22 to);

D28) judge θ ₀＞θ ^*Whether set up,, then make: F if set up _w=F _W0+ Δ F _w, forward steps d 24 to);

D29) the best angle of the crossing θ of output ₀With best bending roller force F _W0

Steps d 25) the objective function B of plate shape described in (X) can be represented by the formula:

B(X)＝((max(σ _1i)-min(σ _1i))/σ ₁)

In the formula:

σ ₁-average forward pull;

Steps d 4) function G of roll shape objective function of optimization design described in (X) can be represented by the formula:

G(X)＝|C _r-C _r0|

In the formula:

C _rThe strip crown value of-calculating gained;

C _R0-Target Board convex value.

The invention has the beneficial effects as follows: this invention is on the basis of a large amount of theoretical researches, in conjunction with on-the-spot rolling situation, production technology characteristic during according to the PC mill milling, take into account the requirement that reduces the angle of the crossing and bending roller force, with the outlet forward pull cross direction profiles value of band as the optimization aim function and a certain proportion of strip crown of assurance as the finish the work optimization of roller roller curve of constraint condition.The working roller curve that goes out designed according to this invention has reduced the angle of the crossing and bending roller force, increased the stability of milling train, improved the serviceable life of working roll, improved the strip crown control ability of PC milling train, not only guarantee the quality requirements of plate shape, and can reach the requirement of commercial Application precision.Simultaneously, according to on-site actual situations, the present invention also can be used for the working roller curve design of any frame.

Description of drawings

Working roller curve parametric solution calculation flow chart when Fig. 1 is PC mill milling band steel;

The best angle of the crossing and best bending roller force when Fig. 2 is the PC mill milling ideal format band steel of embodiment are found the solution calculation flow chart;

Fig. 3 is the working roller curve synoptic diagram of roller curve equation design;

Fig. 4 is the forward pull cross direction profiles figure before and after optimizing.

Embodiment

Below provided when adopting method optimal design 1880PC continuous hot-rolling mill mm finishing mill unit rolled band steel of the present invention, the working roller curve parametric solution process to its 4th frame as depicted in figs. 1 and 2, may further comprise the steps:

(a) collect PC milling equipment parameter and technological parameter:

(835mm～735mm), roll neck diameter 610mm, roller cylinder are apart from 3080mm, elastic modulus 175GPa, Poisson ratio 0.25 for working roll barrel length 1880mm, barrel diameter 785mm, the rigidity 3400kN/mm of monolithic support stressed member beyond the roller system, maximum bending roller force ± 1200kN;

(b) collect the rolling technological parameter that certain typical case is with steel, concrete data are as shown in table 1: (c) with C _2iBe roller curve parameter and optimization variable, set the curvilinear equation of working roll, and get X ₀=[C ₂, C ₄, C ₆, C ₈]=[0.04,0.03,0.02,0.01];

Certain typical case's band steel parameter of table 1

(d) computation optimization goes out the roller curve parameter, comprises the following step of being carried out by computer system:

D1) set bending roller force F _W0=-600kN, the calculating step delta F of given bending roller force _w=50kN, maximum angle of the crossing θ _Max=1.2 °, upper spider angle of the crossing θ ^*=0.3 °, initial angle of the crossing θ ₀=0 °, the calculating step delta θ of the given angle of the crossing=0.01 °, plate shape objective function initial value B _X0=1.0 * 10 ¹⁰, and get calculation times C _n=1;

D2) make angle of the crossing θ=0.01 * (C _n-1);

D3) judge θ 〉=θ _MaxWhether set up,, change steps d 9 over to) if set up;

D4) calculate corresponding band forward pull cross direction profiles value σ _1i

D5) calculate Target Board shape target function value B (X)=34.088;

D6) judge B (X)≤B ₀Whether set up,, then make B if set up ₀=B (X)=34.088, θ ₀=0 °, F _W0=-600kN;

D7) order: C _n=C _n+ 1, forward steps d 2 to)

D8) judge θ ₀Whether set up for＞0.3 °,, then make: F if set up _w=(600+50) kN forwards steps d 4 to);

D9) the best angle of the crossing θ of output ₀=0.25 °, best bending roller force F _W0=400kN;

D10) get Target Board convex value C _R0=0.15mm calculates roll shape optimal design objective function G (X)=2.764 * 10 ^-5

D11) judge whether the Powell condition is set up,, adjust the roller curve parameter X if be false ₀, forward steps d 1 to), set up until the Powell condition, finish to calculate, draw optimum roller curve parameter;

(e) with the roller curve equation of above-mentioned roller curve parameter substitution working roll, the working roller curve equation after being optimized.

Obtain optimum roll shape parameter: X after satisfying optimization establishment condition ₀=[0.12,0.0,0.0,0.0]

Working roller curve equation after promptly optimizing is:

$D_w\left(y\right)=785-0.12{\left(\frac{2y}{L_w}\right)}^2$

The working roller curve synoptic diagram as shown in Figure 3.

As shown in Figure 4, the angle of the crossing and bending roller force all reduce before optimizing, and the forward pull value after the optimization distributes more even, and plate shape is good.G under the former technological parameter (X) value is 0.12141mm, and the G after the optimization (X) value is 2.764 * 10 ^-5Mm has improved the ability of milling train control panel convexity behind visible the optimization.By example as can be seen, this method calculation stability is accurate, reaches the requirement of commercial Application precision.

Claims (4)

1. based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force, it is characterized in that: said method comprising the steps of:

(a) collect PC milling equipment parameter and technological parameter:

Comprise working roll barrel length L _w, barrel diameter D _w, roll neck diameter D _Wj, original convexity curve, roller cylinder distance L _Wf, bending roller force F _w, elastic modulus E _w, Poisson ratio v _w, the stiffness K of monolithic support stressed member beyond the roller system _g, maximum bending roller force F _Wmax

(b) collect the rolling technological parameter that the typical case is with steel:

Band steel supplied materials width B, thickness h, elastic modulus E, Poisson ratio v, rolling temperature T, resistance of deformation σ _s, speed of rolls V _R, front and back mean tension σ ₁, σ ₀, angle of the crossing θ, bending roller force F _w

(c) with C _2iBe roller curve parameter and optimization variable, the curvilinear equation of setting working roll is:

$D_w\left(y\right)=D_w-\underset{i=1}{\overset{4}{\mathrm{\Σ}}}{C}_{2i}{\left(\frac{2y}{L_w}\right)}^{2i}$

In the formula:

D _w(y)-the roller curve distribution value of working roll;

Y-is apart from the distance at working roll middle part;

C _2i-roller curve characteristic coefficient;

(d) computation optimization goes out the roller curve parameter, may further comprise the steps:

D1) given initial curve parameters C _2i

D2) the best angle of the crossing θ of calculating ideal format product ₀With best bending roller force F _W0

D3) calculate roll shape objective function of optimization design function G (X);

D4) judge whether the Powell condition is set up,, adjust the roller curve parameter, forward steps d 2 to if be false), if set up, finish to calculate, export optimum roller curve parameter;

(e) with the roller curve equation of above-mentioned roller curve parameter substitution working roll, the working roller curve equation after being optimized.

2. according to claim 1 based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force, it is characterized in that: the best angle of the crossing θ steps d 2) ₀With best bending roller force F _W0Find the solution, comprise the following step of carrying out by computer system:

D21) set initial bending roller force F _W0, the calculating step delta F of given bending roller force _w, maximum angle of the crossing θ _Max, upper spider angle of the crossing θ ^*, initial angle of the crossing θ ₀, the calculating step delta θ of the given angle of the crossing, plate shape objective function initial value B ₀=1.0 * 10 ¹⁰, and get calculation times C _n=1;

D22) given angle of the crossing θ=Δ θ * (C _n-1);

D23) judge θ 〉=θ _MaxWhether set up,, forward steps d 29 to) if set up;

D24) calculate corresponding band forward pull cross direction profiles value σ _1i

D25) value of calculating ejecting plate shape objective function B (X);

D26) judge B (X)≤B ₀Whether set up,, then make B if set up ₀=B (X), θ ₀=θ, F _W0=F _w

D27) order: C _n=C _n+ 1, forward steps d 22 to);

D28) judge θ ₀＞θ ^*Whether set up,, then make: F if set up _w=F _W0+ Δ F _w, forward steps d 24 to);

D29) the best angle of the crossing θ of output ₀With best bending roller force F _W0

3. according to claim 2 based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force, it is characterized in that: the objective function B of plate shape steps d 25) (X) can be represented by the formula:

B(X)＝((max(σ _1i)-min(σ _1i))/σ ₁)

In the formula:

σ ₁-average forward pull.

4. according to claim 1 based on the PC operation roll of mill roll design method that reduces the angle of the crossing and bending roller force, it is characterized in that: the function G of roll shape objective function of optimization design steps d 3) (X) can be represented by the formula:

G(X)＝|C _r-C _r0|

In the formula:

C _rThe strip crown value of-calculating gained;

C _R0-Target Board convex value.

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