CONSTANT VOLUME ADDING AND RECOVERING DEVICE FOR SPILLED SAND

PURPOSE:To mix spilled sand at a constant rate to knocked-out sand and make the sand quality uniform by driving the conveyor below a spilled sand recovery hopper intermittently according to the amt. of the sand on a knocked-out sand conveyor during molding. CONSTITUTION:A spilled sand conveyor 3 below spplied sand hopper 2 recovering the sand spilled from a mold making machine 1 is installed intersectingly with the upper position of a recovering conveyor 4, and a detector detecting the amt. of knocked-out sand is provided in the middle of the conveyor 4. When large and small knocked-out sands 5 of respectively different sand amts. are conveyed onto the conveyor 4, the detector detects the amt. of the sand and adjusts the operation time of the conveyor 3 according to the detection signal, thereby adding spilled sand 6 in a slightly larger amt. when the amt. of the sand 5 is large and adding the sand 6 in a slightly smaller amt. onto the sand 5 when its amt. is small.