CN-117123624-B - Control method for automatically leveling pinch rolls and ensuring roll shape

CN117123624BCN 117123624 BCN117123624 BCN 117123624BCN-117123624-B

Abstract

The invention relates to a control method for automatically leveling and guaranteeing a coil shape of a pinch roll, which comprises the steps of pressing the pinch roll of a coiling machine, recording the pressure and the roll gap value at two sides of the pinch roll, writing the pressure and the roll gap value into two set stiffness arrays, executing a set pressure value G Is provided with at one side of the pinch roll, finding a corresponding roll gap value Gm according to the stiffness arrays at the same side, finding a theoretical pressure value Fb at the other side of the pinch roll according to the detected roll gap value Gm and combining the stiffness arrays corresponding to the detected roll gap value Gm, carrying out safety limiting on the theoretical pressure value Fb, determining a final executing pressure value G Executing at the other side, and respectively executing the set pressure value G Is provided with and the executing pressure value G Executing at two sides of the pinch roll, so that the roll gap values at two sides are always consistent under different pressures. The invention can always keep the roller gaps at two sides consistent, avoid the coil defect caused by pressure change, greatly reduce the coil repair rate, avoid the loss in the lifting process caused by staggered layers and reduce the quality loss.

Inventors

LI AIMIN
YUE ZHANGLIN
YIN QIAN
LIU YONGQIANG
CHEN ZHITONG
Hou Zhongshi
LI CHENGLIANG

Assignees

邯郸钢铁集团有限责任公司
邯钢集团邯宝钢铁有限公司

Dates

Publication Date: 20260505
Application Date: 20230914

Claims (6)

1. The control method for automatically leveling and ensuring the coil shape of the pinch roll is characterized by comprising the following steps of: s1, pressing pinch rolls of a coiling machine, recording the pressure at two sides of the pinch rolls and the roll gap value, and writing into two set rigidity arrays; s2, executing a set pressure value G Is provided with on one side of the pinch roll, and calculating a corresponding roll gap value Gm according to the same-side stiffness array; S3, calculating a theoretical pressure value Fb on the other side of the pinch roll according to the calculated roll gap value Gm and by combining a stiffness array corresponding to the other side; S4, performing safety limiting on the calculated theoretical pressure value Fb to determine a final execution pressure value G Executing on the other side; S5, respectively implementing a set pressure value G Is provided with and an execution pressure value G Executing on two sides of the pinch roll, so that roll gap values on two sides of the pinch roll are always consistent under different pressures.
2. The method for controlling the automatic leveling and guaranteed rolling of the pinch rolls according to claim 1, wherein the step S1 of pressing the pinch rolls of the coiling machine means that the pressure of the pinch rolls is given by the primary PLC, and the pressure is gradually increased from 0 KN to a value which is not more than 80% of the maximum pressure allowed by the pinch rolls within a range covering the working pressure.
3. The method for controlling the automatic leveling and roll shape assurance of the pinch roll according to claim 2, wherein the primary PLC respectively records the pressure and the roll gap value on two sides of the pinch roll at intervals of 1 KN-5 KN.
4. The method for controlling the automatic leveling and guaranteed rolling of the pinch roll according to claim 1, wherein in the step S3, a theoretical pressure value Fb at the other side of the pinch roll is reversely calculated through ILNL functions, The ILNL function is calculated as follows: , Wherein: F (Z') -the theoretical pressure value Fb to be solved; X n-1 、X n -the n-1 and n pressure values in the stiffness array; Y n-1 、Y n -in the stiffness array, the nth-1 and nth roll gap values; z' -the roll gap value Gm actually performed, which value satisfies the condition Y n-1 ＜Z'≤Y n .
5. The method for controlling the automatic leveling guaranteed coil shape of a pinch roll according to any one of claims 1 to 4, wherein in step S4, the theoretical pressure value Fb is safely limited by an LMT function, specifically, the theoretical pressure value Fb is limited in the range of G Is provided with X (1±x%), if the theoretical pressure value Fb is out of the range, G Is provided with X (1±x%) is executed, and thus the final execution pressure value G Executing on the other side is obtained; LMT function, the function is described as follows: , Wherein: p (Fb) -the execution pressure value G Executing to be solved; fb-theoretical pressure value; g Is provided with -set pressure value on one side.
6. The method for controlling the automatic leveling of the pinch roll to ensure the coil shape according to claim 5, wherein the value range of x% is 5% -25%.

Description

Control method for automatically leveling pinch rolls and ensuring roll shape Technical Field The patent application belongs to the technical field of hot rolled strip steel production in the metallurgical industry, and more particularly relates to a control method for automatically leveling and guaranteeing coil shape of a pinch roll. Background The coiling machine is coiling equipment for hot continuous rolling of plate and strip, and is generally composed of a pressure head roller, a pinch roller, a wrapper roller, a mandrel device and the like, wherein the pinch roller is positioned at the inlet side of the coiling machine and is composed of an upper supporting roller and a lower supporting roller (a lower pinch roller and an upper pinch roller) with unequal roller diameters, and the coiling machine mainly comprises a coiling machine for guiding the head of strip steel and a coiling machine for setting up the strip steel to maintain tension after finish rolling and steel throwing. The lower pinch roll is in a fixed mode, the balance and lifting of the upper pinch roll are realized through hydraulic cylinders which are independently arranged on two sides of the pinch roll and provided with position sensors, the roll gap and the pressure of the pinch roll are controlled by a hydraulic servo valve, and each hydraulic cylinder is set through the pressure, so that the weight of a transmission shaft of the upper pinch roll can be automatically balanced. The roll gap of the pinch roll is completed through lifting of the upper pinch roll. The roll gap of the pinch roll is preset according to the thickness of the strip steel, and after the head of the strip steel enters the pinch roll, the pinch roll is changed from roll gap control to pressure control, and the pressure setting can be performed according to a manually maintained material specification table. The automatic control of the pinch roll comprises pinch roll gap control, pinch roll speed control, pinch roll reduction control, pinch roll cooling control and the like. The control action steps of the pinch roll are as follows: When the coiling machine is selected to coil the next strip steel, the upper pinch roll descends from a standby position to a standby position set by L2 (a secondary control system of a strip production line), and at the moment, the pinch roll adopts a position control mode; after the strip steel enters the coiling machine and tension is established between the strip steel and the mandrel, the pinch roll is changed from a position control mode to a pressure control mode, and the strip steel is in a front tension control mode at the moment, and the strip steel tension is mainly generated between the mandrel and the finishing mill; after F1 (first rolling mill of finishing mill group) throws steel, the strip steel is changed from a front tension control mode to a rear tension control mode, the pinch roll is still pressure controlled no matter the front tension control mode or the rear tension control mode, the pinch roll pressure is increased, and the strip steel tension is mainly generated between the pinch roll and the mandrel. If F1 (finishing mill first stand) has thrown steel before the coiler builds tension, there is no front tension control and the position control mode is directly changed to the rear tension control mode. When the tail of the strip steel reaches a certain distance in front of the pinch roll (the distance can be adjusted according to the field condition), the pinch roll is turned into a position control mode, and the position of the upper pinch roll is kept still. After the tail part of the strip steel leaves the pinch roll, the pinch roll rises to a standby position, and the coiling action is finished. In the process, when the pinch roll is in a back tension control mode, the pressure at two sides of the pinch roll is increased in the same proportion, and the actual roll gaps at two sides are different due to different rigidities at two sides, so that axial driving force is generated on the strip steel, the boss at the tail of the strip steel is staggered, hanging damage and rolling repair are caused, and the phenomenon is intolerable in a production link. Disclosure of Invention The invention aims to solve the technical problem of providing a control method for automatically leveling a pinch roll to ensure the shape of the roll, which can avoid the occurrence of the staggered layer phenomenon of a boss at the tail part of strip steel, so that the strip steel is stably coiled, a good roll shape is obtained, the hanging injury and the roll shape repair are reduced, and the problems in the background technology are solved. In order to solve the problems, the invention adopts the following technical scheme: a control method for automatically leveling and ensuring coil shape of a pinch roll comprises the following steps: s1, pressing pinch rolls of a coiling machine, recording the pressure at two sides of the pinc