METHOD AND DEVICE FOR SPRAY MOLDING

摘要

PURPOSE:To prevent the adverse influence of pulsation in the initial period of spray packing and to perform spray-packing respectively according to the facing sand layer and the backing sand layer by controlling respectively the spray-packing pressures according to the respective stages for forming the facing sand layer of a self-curing molding material and forming the backing sand layer thereof. CONSTITUTION:The refractory particulate material of fine grains stored in one of two- tank type storage tanks 15 is supplied into a mixing trough 21 and further a binder and hardener are respectively fed 25, 26 into the trough 21 and are mixed 23. The resulting self-curing molding material (material A) is supplied from the top end side of the trough 21 into a compressed air injector 27 where the material is accelerated by the compressed air injected from said device and is thus spray-packed into the prescribed molding flask contg. a casting pattern from a spray hose 31. The material A is spray-packed to the surface of the casting pattern by controlling 32 the initial speed of the spray packing to 80-100m/sec, by which the facing sand layer having a prescribed thickness is formed. The refractory particulate material of coarse grains stored in the other of the tanks 15 is spray-packed on the facing sand layer at a spray packing speed of 30-50m/sec at the same operation as mentioned above to form the backing sand layer. The spray molding is thus completed.