PURPOSE: To prevent leakage of gas by connecting a gas supply pipe installed along with an air inlet pipe of a closed gas generating container to a molding flask provided with a reduced pressure chamber, and thereby sucking supplied gas to the reduced pressure chamber through casting sand in the molding flask.
CONSTITUTION: An air inlet pipe 20 having plural small holes 18, with upper end projected to outside and lower end submerged in solution 19 in L-shape is installed in a closed gas generating container and connected to a valve 17. A gas supply pipe 15 is installed adjoining to and parallel with the inlet pipe 20, and its lower end is opened to a space in the container 16 and upper end is connected to a gas supply hole 11 of a cover 9 that covers airtightly a molding flask 6 on a pattern plate 1 provided with a reduced pressure chamber 2 through a conduit 14. When the gas in the gas generating container 16 is sucked to the molding flask 6 through the supply pipe 15 and conduit 14 by actuating a vacuum pump, the gas is sucked and removed through casting sand 8, the vent 3, reduced pressure chamber 2 and suction pipe 23.
MATSUI KAZUHARU
TOYODA SHIGEHIRO
| JPS4714265A | ||||
| JPS4840528A | 1973-06-14 | |||
| JPS4832054A | 1973-04-27 |