GB1193470A - Apparatus for Casting Meltable Material such as Metal under Gas-Pressure and -Counterpressure - Google Patents

Abstract

1,193,470. Casting-machines. INSTITUT PO METALOZNANIE I TECHNOLOGIA NA METALITE. 24 Aug., 1967 [15 Sept., 1966], No. 39092/67. Heading B3F. In apparatus for gas pressure casting, with counter-pressure in the mould 2, the pressures being selected to control the rate of filling of the mould, a valve 1 (in a wall of the feed system, Fig. 1, or in a mould wall that contacts the metal during casting, Fig. 2) is left open (when gas from a cylinder 5 is building up a required pressure in the apparatus) to balance the pressures in the mould cavity and in a chamber 3 surrounding the melt container 4. When the pressure has built up as required, the valve 1 is closed and charging of the mould 2 is started and controlled by gas inlet valves 7, 8 and an outlet valve 10. Restricted vents 11 to a chamber 12 around the mould allow gas displacement as the melt enters the mould. In the embodiment of Fig. 2, the valve 8 may be regulated to balance resistance created by gasflow (because of the further interconnection of the mould 2 and chamber 3 through the valves 7, 8) but to eliminate this necessity an equalizing valve 13 may connect the chambers 11, 12. In the arrangement of Fig. 2, the valve 1 may be constituted by a movable section of the mould wall, Fi4. 5 (not shown), or the whole mould may be lifted from the feed pipe 9. In a modification, Fig. 4 (not shown), openings in the lower end of the feed pipe 9 constitute the valve 1 and are closed by dipping of the end into the melt by relative movement of the parts by raising or lowering, by swinging of the pipe or by raising the melt level by electromagnetic pumping.