Abstract: The invention relates to a valve device for a pressure injection or die-casting machine, said device comprising a body (18) with a valve chamber (21) including a suction chamber and a control chamber, and a sliding valve (20) mounted in the valve chamber, said sliding valve comprising a first portion (34) with a valve head (44) that co-operates with a valve seat (22) on the body in order to open and close the valve and a second portion (35) comprising a piston (38) mounted in the control chamber (21a). The control chamber is connected to fluid control connections (26a, 26b) in order to exert a pressure on the piston (38) so as to control the opening and closing of the valve. The second valve portion and the first valve portion are aligned on the same axis in the direction of movement of the sliding valve and said first and second portions of the sliding valve can be separated from one another and secured to one another using a removable securing member (36, 36?).

Abstract: The invention relates to a valve device for a pressure injection or die-casting machine, said device comprising a body (18) with a valve chamber (21) including a suction chamber and a control chamber, and a sliding valve (20) mounted in the valve chamber, said sliding valve comprising a first portion (34) with a valve head (44) that co-operates with a valve seat (22) on the body in order to open and close the valve and a second portion (35) comprising a piston (38) mounted in the control chamber (21a). The control chamber is connected to fluid control connections (26a, 26b) in order to exert a pressure on the piston (38) so as to control the opening and closing of the valve. The second valve portion and the first valve portion re aligned on the same axis in the direction of movement of the sliding valve and said first and second portions of the sliding valve can be separated from one another and secured to one another using a removable securing member (36, 36?).

Abstract: In the venting valve device for die-casting, the evacuation valve which is intended to be closed comprises an evacuation piston and is actuatable by a pneumatic control piston which is in the form of a double-acting differential piston, whereby one of its pressure surfaces is supplied with compressed air by a high response valve in order to open while its other pressure surface is supplied with compressed air by a second control valve in order to close. The high response valve is provided with a vent in order to reduce the pressure maintaining the control piston in the open position within a very short time and thus to ensure a very short closing time of the evacuation piston. While being simple in construction, such a venting valve allows a very short closing time and is therefore particularly suitable also for high-speed die-casting.