Rapid strip breakage detection and protection method and device based on rolling mill moment

Abstract

The invention relates to a rapid strip breakage detection and protection method and device based on rolling mill moment. The method includes the steps that communication is built among a master control PLC, a rolling mill frequency converter, a left recoiling machine frequency converter, a right recoiling machine frequency converter and a depressurization system to transmit strip breakage detection and protection signals. According to the rolling speed, a moment strip breakage detector is input, change conditions of a rolling mill moment value and a strip breakage threshold value output by a parameter adapter are monitored, whether strip breakage occurs or not is rapidly captured, a strip breakage occurrence signal and a strip breakage position signal are output; an adaptive relationship between rolling mill rolling loads and strip breakage parameters is built, and the requirements for rapid strip breakage detection and detection accuracy are rapidly met through parameter setting and optimizing; strip breakage protection is executed under a set strip breakage protection rule, according to the strip breakage occurrence signal and the strip breakage position signal, strip breakage protection is executed according to the control flow, a roller gap is rapidly opened, strip breakage strip steel smoothly leaves a rolling mill, and the rolling mill and a strip breakage side recoiling machine can be suddenly stopped with larger energy.

Description

technical field [0001] The invention relates to a control method for a coil production process unit, in particular to a control method for detecting and protecting cold-rolled strip breaks. Background technique [0002] When the 20-roll reversing mill rolls cold-rolled strips, the problem of broken strips often occurs, and the broken strips will cause different degrees of loss to the unit: at least it will cause the unit to stop for a short time; Finally, the production can be resumed after reorganization, but it will also cause the "twisted belt" inside the rolling mill and the "loose coil" of the steel coil on the coiler. When the strip steel is twisted into the rolling mill, under the effect of heat, the strip steel fragments will stick to the surface of the roll and cause damage to the roll surface. The damaged roll surface is unusable, which not only causes the cost of roll consumption to increase, but also requires a new roll change to resume production. figure 1 It ...

AI Technical Summary

Problems solved by technology

[0002] When the 20-roll reversing mill rolls cold-rolled strips, the problem of broken strips often occurs, and the broken strips will cause different degrees of loss to the unit: at least it will cause the unit to stop for a short time; After that, production can be resumed after reorganization, but it will also cause "twisted belt" inside the rolling mill and "loose coil" of steel coils on the coiler

Because the direct tension measurement method needs to install two sets of tension measuring instruments, new hardware investment is required, which often increases the project cost, and the tension measuring instrument has a longer distance from the rolling mill, and there is also a detection lag, and the reflection speed is slower, which will cause twisted belts inside the rolling mill. often fail to meet production requirements

[0004] It can be seen that the above two broken belt detection methods can correctly detect the broken belt and then implement the broken belt protection when the unit breaks, but because of the slow response speed, they often cannot meet the requirements of reducing the broken belt loss.

Images