Piston-cylinder unit with variable sealing element - used in metal pressure die casting machine

摘要

Piston/cylinder unit, for transport, compression or evacuation of a medium, has a variable sealing element between the piston and the cylinder, the piston/cylinder unit is associated with an adjuster (13) which is controlled by a control unit and which acts on the sealing element (23) to effect sealing action changes which are dependent on the piston path and/or position. USE/ADVANTAGE - Claimed use of the piston/cylinder unit is for feeding molten metal (3) into the die of a pressure die casting machine, esp. of the cold chamber type with an evacuated die cavity. The variable sealing action of the sealing element allows prodn. of high quality die castings.