| 摘要 |
PURPOSE:To prevent easily and inexpensively the drop of sand from a sand mold by spraying water glass on the surfaces in the product part, sprue and runner of the sand mold and hardening the same with gaseuous CO2. CONSTITUTION:A pattern 1 is fixed in a molding flask and is fixed with molding sand 2 to form a sprue 3 perpendicularly. A top sand mold 4a and a bottom sand mold 4b are spaced from each other and the pattern 1 is removed. Then, a product part 5a and a runner 6 are formed on the bottom surface of the mold 4a and a product part 5b is formed on the top surface of the mold 4b, respectively. Water glass 8 is then sprayed by using a sprayer 7 to the surfaces in the product parts 5a, 5b, the runner 6 and the sprue 3 so as to be stuck thereon. The mold 4a and the mold 4b are mated with each other, and gaseous CO2 is introduced through the sprue 3 into the product part 5 and the runner 6 to harden the water glass stuck on the surfaces thereof, whereby the strong casting mold is obtd. |
