Closing device on a plastic injection molding machine

Closing device for a mold closing unit of a plastic injection molding machine for processing plastics materials and other plasticizable substances, said device comprising:

• at least one hydraulic pressure cylinder unit for generating a mold closing pressure on an injection mold which is accommodated in a mold clamping chamber;
• a pressure piston disposed in the pressure cylinder unit, a piston rod of the pressure piston is disposed along a central axis of the pressure cylinder unit, and the pressure piston separates a high-pressure chamber of the pressure cylinder unit from a low-pressure chamber;
• an hydraulic drive cylinder associated with the pressure cylinder unit for closing the injection mold assembly, which drive cylinder is disposed concentrically relative to the central axis, and an actual cylinder of the drive cylinder is formed by the pressure piston of the pressure cylinder unit;
• and
• an hydraulic compensating cylinder associated with the pressure cylinder unit for receiving or respectively dispensing hydraulic medium, which comes from the pressure cylinder unit or respectively is to be dispensed to said pressure cylinder unit, and comprising a compensating cylinder chamber being in open communication with the low-pressure chamber of the pressure cylinder unit,
• wherein the compensating cylinder is likewise disposed concentrically relative to the central axis.