Tension system optimization method for suppressing vibration of cold tandem rolling mill

Patent metadata

Field	Value
Publication number	US-11534807-B2
Application number	US-201917258888-A
Country	US
Kind code	B2
Filing date	Jul 24, 2019
Priority date	Jul 26, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

The application discloses a tension system optimization method for suppressing vibration of a cold tandem rolling mill. The method aims to suppress vibration occurring in a high-speed rolling process of a cold tandem rolling mill, and provides a rolling machine vibration determination index coefficient for effectively determining whether vibration occurs in a rolling machine. The method employs a target optimization function F(X) such that a mean square error between an optimal value ψ0i of the rolling machine vibration determination index and a vibration determination index ψi of each machine frame acquired in an actual rolling process is at a minimum, and such that a maximum value of the rolling machine vibration determination index coefficient of each individual machine frame is also at a minimum, employs a constraint in which an upper threshold ψi+ of the vibration determination index is acquired during a rolling process in an over-lubricated state in which a neutral angle γi coincides with a bite angle αi and a constraint in which a lower threshold ψi− of the vibration determination index is acquired during a rolling process in an under-lubricated state in which the neutral angle γi is half the bite angle αi, thereby ultimately optimizing a tension system of a rolling process of a cold tandem rolling mill.

First claim

The invention claimed is:

1. An iterative method for suppressing vibration of a cold tandem rolling mill, the mill comprising a plurality of machine frames for processing steel strips, by optimizing the inlet tension value and the exit tension value for each of the plurality of frames, where the dimensional and process operational parameters of the rolling mill are defined as follows:
R i is a radius of a work roll of each machine frame;
ν ri is a surface linear speed of a work roll of each machine frame;
Ra ir0 is the original roughness of the work roll of each machine frame;
B Li is a roughness attenuation coefficient of the work roll;
L i is a rolling distance in kilometers of the work roll of each machine frame after exchange of the work roll, wherein, i=1, 2, . . . , n, represent the ordinal number of machine frames of the cold tandem rolling mill;
n is the total number of machine frames;
E is the elastic modulus of a steel strip;
ν is a Poisson's ratio of the steel strip;
B is the width of the steel strip;
h 0i is the inlet thickness of the steel strip for each machine frame;
h 1i is the exit thickness of the steel strip for each machine frame;
K is the value of the deformation resistance of the steel strip;
P i is the rolling force of each machine frame;
ν 0i is the inlet speed of the steel strip in front of each machine frame;
k c is the influence coefficient of an emulsion concentration;
θ is the viscosity compression coefficient of a lubricant;
η 0 is the value of the dynamic viscosity of the lubricant;
α is a bite angle for each machine frame and is the angle defined by the surfaces of the steel strip and a working roller;
ψ i + is an upper threshold of a vibration determination index at an over-lubricated critical point at which a neutral angle coincides with and is equal to a bite angle, corresponding to a friction coefficient of a value at which slippage occurs between the steel strip drawn from the work roll and a region where a rolling force P is applied to the steel strip, thereby causing vibration of the rolling mill;
ψ i − is a lower threshold of the vibration determination index at an under-lubricated critical point at which the neutral angle is half the bite angle, and at the point, an oil film between the work roll and the steel strip is prone to rupture, thereby causing the friction coefficient to increase suddenly, resulting in abnormal rolling pressure fluctuations, thereby causing vibration of the rolling mill;
T 0i is the inlet tension value of each machine frame,
T 1i is an exit tension value, wherein
T 01 =T 0 and T 1n =T 1 ,
the method comprising the steps of:
(i) assigning an initial set value of a current target tension system optimization function for suppressing vibration of the cold tandem rolling mill: F 0 =1.0×10 10 ;
(ii) setting initial tension systems T 0i and T 1i , wherein T 0i+1 =T 1i ;
(iii) for each machine frame, calculating a bite angle α i as follows:

α
i

=

Δ
⁢

⁢

h
i

R
i
′

,

where, Δh i =h 0i −h 1i ,
R i ′ is a flattening radius of the work roll of the i th machine frame, and

R
i
′

=

R
i

[

1
+

1
⁢
6
⁢

(

1
-

ν
2

)

⁢

P
i

π
⁢
E
⁢

B
⁡

(

h

0
⁢
i

-

h

1
⁢
i

)

]

;

(iv) calculating an oil film thickness ξ i in a current tension system as follows:

ξ
i

=

h

0
⁢
i

+

h

1
⁢
i

2
⁢

h

0
⁢
i

·

k
c

·

3
⁢

θη
0

⁡

(

Assignees

• Baoshan Iron & Steel

Inventors

• Wang Kangjian
• Zheng Tao
• Li Shanqing
• Chen Xiaoming
• Qu Peilei

Classifications

• B21B37/007 Primary

  Control for preventing or reducing vibration, chatter or chatter marks (B21B37/66 takes precedence) · CPC title

• B21B37/48 Primary

  Tension control; Compression control · CPC title