Reconstruction Of Electrical Control System Of Sand Muller

With the development of the market economy, technical reconstruction must be carried out by the enterprises,in order to enhancing competitive power and improving productivity industrial.In the process of reconstruction, although process flow and equipment is important, but automation transformation is also absolutely necessary, Even high productivity and low investment can be achieved. PLC is often used in field-date acquisition and equipment control because of its powerful function,easy application and high reliability.According to the actual needs of foundry equipment, modern control technology, control theory,information technology and other technical knowledge, a improved electric control system of sand Muller was formed based on the existing technology of sand muller. Programmable logic controller (PLC) is used to control the peripherals and attachments of the entire sand muller, This improved the reliability of the system and achieve the requirements of production process automation, and efficient large-scale production.This paper first introduces the structure and working process of the sand muller, parts of the reconstruction electrical control system, the requirements after the reconstruction, the PLC features, working principle and selection method. Then it introduces the selection of the necessary hardware, including the selection of PLC module, weighing sensor, weighing terminal and man-machine interface. The author not only designs the electrical control system of main circuit and control circuit and introduces its principle of work but also designes hardware and software parts of the PLC, draws the sequential function chart of PLC main control part and design a PLC ladder according to sequential function; finally the paper introduces the connect debug and cautions of system .The control system of sand muller has the characteristics such as high automation, high efficiency and it use programmable controller as nucleus equipment to data acquisition and processing .Advanced hardware technology and Optimized software design improve the reliability of system greatly and can achieve control of unmanned management ,it has system reliability, low failure rate and greate economic benefits.