METHOD AND DEVICE FOR PRODUCING SHELL MOLD

PURPOSE:To reduce the time for sintering and curing and to improve the efficiency of producing a shell mold in the stage of producing said mold by blowing hot wind to shell sand to calcine and cure the shell sand in combination with the temp. of preheated dies. CONSTITUTION:The upper and lower dies 2, 3 are preheated and the temps. thereof are held by a heater, etc. The shell sand is blown from a blow head 5 through a bushing 4 for blowing in such a state to start packing the shell sand into a cavity 8. A stop valve 13 is driven to open by a timer 14 to pass the air from a pessure air source 12 to the line on the down stream of the valve when the start of packing the shell sand is detected. The time for supplying the air is controlled by the timer 14. The air is heated in the course of flowing through the passages 7, 9 of the dies 2, 3 and is ejected and supplied in the hot wind state into the cavity 8 so as to arrive at the inside of the sand packed therein. An initially cured layer is thus formed to the packed shell sand by the die temp. and the inside of the surface is heated by the hot wind, by which the heating and curing are accelerated.