The Research And Application On The Flying Shear Line Of Blooming Mill In Long Product Department AC Frequency Control Modification And APC Control Technology Optimize

Flying Shear Line is the main critical equipment of rolling line in Baosteel, mainly used for segment shear processing of the billet and tube blank by scale and double lengths. As the changes in market demand in recent years, Baosteel continues to develop high-alloy wire products, bloom continuous casting slab is basic early by rolling production line for subsequent rolling, the original flying shear line has been difficult to adapt to the production of new products demand, the existing shear can not meet the current situation of steel production, much less to meet the needs of the changes in the market demand and bloom continuous casting in3to5years. And the original equipment machinery and equipment is serious aging, the electrical system is aging, precision, loss of accuracy, replacement difficulties, therefore it is imperative of the transformation of existing units.The flying shear original unit is designed to crank four-bar linkage, shear blank is made of carbon steel and low alloy steel. The electrical drive system is the analog speed control system for the introduction of the Hitachi80’s. power supply is adopt the transformer-silicon controlled rectifier-motor unit; magnetic field one-way control mode, the double-loop speed control system of DC armature reversible. APC positioning control software polynomial fitting curve by the PLC; thyristor power components adopt the thyristor and silicon controlled rectifierThis paper is about the transformation of flying shear combined input-output unit and running stability and reliability factors, determined the scope of reform, the electrical control system solutions, transmission control system, automatic positioning control and implemented. View of the overall transformation is only through the method of overall introduction or cooperation, the high investment in equipment, long construction period, the drawback above determine the partial renovation of the unit process equipment and electrical control system overall renovation in the program. Consider characteristics of the flying shear driving, the development direction of the unit electric transmission system and the amount of on-site maintenance and other factors communicate with ABB, TMEIC, Siemens and several domestic manufacturers, determined to adopt the Siemens asynchronous motor and AC-DC-AC variable frequency drive. According to the transmission system control needs, append S7PLC controller realizes inverter control and the angle of the cutting edge zero correction, APC calculation and control functions. Retaining the original rolling line exports auxiliary control, the definite length calculation, and the flying shear start command functions of the original GE90-70PLC, and concerned the defect of the low precision of the original APC polynomial fitting method of the original control system, the APC control method is optimized, and the exponential curve control APC technique is used.After the flying shear partial reconstruction unit, the maximum shear section increased from145to147square. Maximum shear force increased from189to200tons. Not only improve the shear capacity of the flying shear, but also improve the level of equipment and equipment support capabilities. It enhances the market competitiveness of Baosteel on long products, and also meets the market’s needs of production and quality.