Vacuum die-casting system and method for operation of such a vacuum die-casting system

1. A vacuum die-casting system comprising

a casting chamber having a filling opening and an inner wall,

a casting piston able to be moved in the casting chamber and having an outer mantle,

a piston rod connecting the casting piston with a casting drive, and

an evacuator comprising a vacuum system and comprising at least one suction pipe having a first end and a second end,

wherein a ring gap is configured between the outer mantle of the casting piston and the inner wall of the casting chamber, and wherein the casting piston has at least one depression or hollow standing in a flow connection with the ring gap and able to be evacuated,

wherein the evacuator is able to evacuate the at least one depression or hollow,

wherein the first end of the at least one suction pipe is connected with the at least one depression or hollow, in terms of flow technology,

wherein the second end of the at least one suction pipe is connected with the vacuum system, in terms of flow technology,

wherein the at least one suction pipe runs along the piston rod on the outside of the piston rod,

wherein the first end of the at least one suction pipe makes a transition into the at least one depression or hollow via a piston region or a work piece region facing the piston rod, and

wherein the at least one suction pipe is connected with the piston region or the work piece region, in terms of flow technology.

2. The method for operation of a vacuum die-casting system according to claim 1 , the method comprising steps of:

a) introducing a casting melt into the casting chamber, through the filling opening,

b) moving the casting piston until the at least one depression or hollow has gone past the filling opening, or tightly closing the filling opening and, if necessary, moving the casting piston until the at least one depression or hollow is positioned in the casting chamber, and

c) evacuating the at least one depression or hollow via at least one suction pipe running on the outside of the piston rod in a manner so that less to no gases or air flow(s) into the casting chamber through the ring gap.

3. The method according to claim 2 , wherein the evacuation of the at least one depression or hollow is started by way of at least one of a path control and a time control.