| 摘要 |
PURPOSE:To improve workability, by a method wherein a portion, positioned downward from a lower on-off valve mounted to an intermediate part in a casing, forms a space part for pressing sand, and a space part for stocking sand is formed between an upper on-off valve and the lower on-off valve. CONSTITUTION:After a casing 2 is driven by an exciter 4, an upper on-off valve 5 and a lower on-off valve 6 are opened, and a specified amount of sand is charged through a hopper 3 for supplying sand in a space part 10 for pressing sand. Thereafter, the on-off valve 6 is closed, a compressed air is fed through a nozzle 12 to the space part 10, and sand is charged through the hopper 3 in a space part 9 for sand stock. As the casing 2 is pulled off in a condition to press the sand in the space part 10 by means of the air, sand is pushed out from a lower end to form a sand pile part p1. Further, the on-off valve 6 is opened and the on-off valve 5 is closed, and after the sand, stocked in the space part 9, is dropped and charged in the lower part of the space part 10 through the on-off valve 6 as a compressed air is fed downward through a nozzle 11, sand piles P1, P2... are formed in a similar manner as described above. |
