DEVICE FOR AUTOMATICALLY SUPPLYING MOLDING SAND INTO BLOW HEAT IN MOLDING MACHINE

摘要

PURPOSE:To automatically supply molding sand into a blow head from a sand replenishing tank by communicating the blow head and the sand replenishing tank through a duct and making the inner pressure difference between the blow head and the sand replenishing tank with exhausting operation of a gas supplying/exhausting valve arranged on the blow head. CONSTITUTION:After press-contacting the blow head 1 to a metallic mold with a press-contacting cylinder 7, by changing over the gas supplying/discharging valves 4, 4', compressed air is introduced from a compressed air source 6, and by making the inner parts of the blow head 1 and the sand replenishing tank 2 under pressurized condition, the molding sand is blown into cavity in the metallic mold. After the blowing completes, by opening the gas supplying/exhausting valve 4, the compressed air in the blow head 1 is exhausted. That is, the pressure in the blow head comes to lower than the pressure of the sand replenishing tank 2 and the pressurized air in the sand replenishing tank 2 is caused to flow into the blow head 1 through the duct 3, and the molding sand is automatically supplied to the blow head. By opening the gas supplying/exhausting valve 4', the compressed air in the sand replenishing tank 2 is exhausted and the supply of the sand into the tank 2 is executed from a hopper by opening the replenishing hole to shift to the following blowing stage.