Research On Device For Fast Testing Permeability And Compactibility Of Green Sand And Compaction Of Mould

Permeability, compactibility and mould compaction are important performance characteristics of green sand and mould. It has great meaning for improving casing quality, evaluating compact method and reducing produce cost that green sand permeability, compactibility and mould compaction can be measured conveniently on the foundry workshop.A new portable testing instrument of green sand permeability, compactibility and mould compaction is studied in the thesis, including the device frame, design of hardware and software and testing result comparisons between the new instrument and standard experimental method.The new device consists of fast specimen maker, compressed air source, permeability detector, displacement sensor and data sampling and processing unit. Because of the special structure of specimen tube, main tube and assistant tube, and the flexible ramming head based on automatic pressure maintaining principle, the speed and precision of the specimen maker are ensured. Permeability is measured by constant pressure air source blowing, core of the detector is micro differential pressure sensor. A displacement sensor based on solenoid principle is used to measure green sand compactibility and mould compaction. The data sampling and processing unit consists of micro controller AT89C52, LCD display and AD converter TLC2543, samples pressure signal and displacement signal in real time,calculates parameters and displays testing results. The main program and subroutines are programmed in C language. Comparison experiments between the new instrument and standard experimental method indicate that the new instrument not only has the advantages of compact and portable structure, but also easy to operate and the measurement results are exact. It is suitable for fast testing of green sand quality parameters on the foundry...