Pouring Plaster-based Anti-gravity Research And Application Of Control Systems

The application of the control system in the antigravity pouring has been researched combining with the high quality castings processing in this thesis.First the system analysis of the constituent, controlled member and the control process in low pressure casting is carried out. After the process experiments of low pressure casting, the internal quality influences caused by the low pressure casting and the normal gravity casting are compared, therefore the series of control parameters of high quality castings production are generalizedSecondary the counter-pressure casting principles, equipment composition, the liquid level control method are analyzed. By the pilot production of thin-wall castings, the comparison of different influences between the counter-pressure casting and the gravity casting is carried out in the thesis, then the process control principles of counter-pressure casting are concluded.It is proved in the pilot production that the control system runs effectively in the plaster casting. The internal quality can be improved; the gas cavity and the shrinkage porosity can be reduced by proper control of the process. The tensile strength will raise 20%, the elongation will raise 50～100%, the quality of casting products can be improved from II to I.