APPARATUS FOR LOADING PRESSURE TO PRESSURIZING MECHANISM OF PRESSURE CASTING MACHINE

1. Apparatus for the pressure-charging of the press cylinder of a die-casting machine, especially a cold-chamber die-casting machine with three-phase working system, in which the press-in part consists of a press cylinder (1) with single-stage press piston (4) and at least the filling-, final- and after-pressure necessary for the second and third phases is supplied from a fluid-filled high-pressure reservoir (7a, 7b) under gas pressure, while the pressure for the first phase can be supplied by a system separated from the high-pressure reservoir (7a, 7b), characterised by the following features : (a) a compensating reservoir (8a, 8b) valve lessly opens into a connecting conduit between high-pressure reservoir (7a, 7b) and press cylinder (1), (b) the gas-charged high-pressure reservoir (7a, 7b) consists of a gas-filled high-pressure vessel (7a) and a high-pressure cylinder (7b) placed thereafter in the direction towards the press cylinder (1) with piston (10) displaceable therein to separate the hydraulic fluid from the gas of the high-pressure vessel (7a) loading the high-pressure cylinder (7b), (c) the compensating reservoir (8a, 8b) consists of a gas-filled compensating vessel (8a) with compensating cylinder (8b) placed thereafter in the direction towards the press cylinder (1), with piston (11) displaceable therein to separate the hydraulic fluid from the gas of the compensating vessel (8a) loading the compensating cylinder (8b), (d) the pressure in the compensating reservoir (8a, 8b) is lower than the pressure in the high-pressure reservoir (7a, 7b), (e) into the connecting conduit leading from the high-pressure reservoir (7a, 7b) to the press cylinder (1), between the compensating reservoir (8a, 8b) opening into this connecting conduit and the high-pressure reservoir (7a, 7b) there is arranged a valve (9) which is opened only during the course of the second and third working phases.