Design Of PLC-based Flying Shear Control System Of Bars

Indispensible for product line of rolled steel, flying shears are mainly used for shearing heads and tails of moving rolled parts at a specified length. Thus, the quality of flying shears directly determines yield and rate of fixed length, imposing direct impacts upon benefits of enterprises that manufacture rolled steel.With the increase of rolling speed in modern product lines of bars and wires, the requirements for electric control system of flying shears are becoming increasingly higher. In this case, flying shears are required to be more responsive with higher shearing accuracy and lower failure rate. On the premise of this, equipping PLC (programmable logic controller) of mature performances with efficient DC speed control system is a reasonable and economical method for controlling flying shears.This paper focuses on examining precise automatic control of start-stop type flying shears with the support of SIEMENS6RA70fully digital DC speed controller on the premise of matching GE90-30PLC with high-speed counter module and axis positioning module. Besides, models and designs are selected for hardware and software of flying shear control system. Control programmes for shearing length and precision are analyzed from the perspective of principles and mathematics, so as to configure external wiring and field I/O of PLC for the purpose of regulating SIEMENS6RA70fully digital DC speed controller. Furthermore, PLC is programmed with Logicmaster90programming software to meet control requirements. With the application of GP-PRO/PB Ⅲ software, upper-level computer monitoring is made available on the remote touch screen."Main Menu","Function Selection","Parameter Setting","Monitoring" and "Diagnostic Function", etc are designed.At last, the entire system is debugged and tested. In addition, new problems are solved, so good effects are achieved in trial operation and expected functions are generally accessible in the whole system. Hence, evidences are provided for verifying effectiveness and reliability of the design.