Die-casting machine with automatic air purge system

An injection assembly of a die casting machine, comprising:

• an injection piston, controllable in translation for working on mold cast metal in a mold of the machine, and a main pressure chamber for containing and pressurizing the fluid for the translation of the injection piston;
• a multiplier piston hydraulically controllable to increase the fluid pressure in the main pressure chamber;
• at least one valve for controlling the advance and return of the injection piston and the multiplier piston, wherein the at least one valve comprises at least one of:
• a proportional, electronically controllable delivery valve with feedback via a position transducer, an injection discharge check valve, an injection check valve, a proportional, electrically controllable, injection discharge valve with feedback via a position transducer, a multiplier release valve, a multiplier discharge check valve, a proportional, electronically controllable, main multiplier valve with feedback via a position transducer;
• and
• an electronic control operatively connected to at least one of the at least one valve and to the transducers for controlling the opening and closing of the at least one valve, the electronic control configured with a predetermined control program comprising an execution program for an air purge cycle that alternately opens and closes the valve for a predetermined number of times.