Disclosed is a hydraulic system for a molding system, the molding system having a clamp actuator and an injection actuator, the hydraulic system comprising a clamp accumulator for storing hydraulic fluid for use in actuating the clamp actuator; an injection accumulator for storing hydraulic fluid for use in actuating the injection actuator; a pump for conveying hydraulic fluid to the clamp accumulator and the injection accumulator; and a selector valve for selectively fluidly connecting the pump to one of the clamp accumulator and the injection accumulator.

A toggle lever clamping unit for an injection moulding machine includes fixed and movable platens, a support plate, a toggle lever mechanism operatively connected with both the support plate and the movable platen, a cross clamp operatively connected with the toggle lever mechanism and movable along a machine longitudinal axis, and an electric drive for moving the cross clamp. In addition, a hydraulic drive is operatively connected with the cross clamp and includes a fluid-operated piston cylinder system, with the lengths of the cylinder and the piston rod being coordinated with one another such that the hydraulic drive follows a travel path of the cross clamp as the movable platen travels between an open position of the clamping unit, in which the toggle lever mechanism is swung in, and a closed position in which the toggle lever mechanism assumes a predeterminable extended position and a clamping force is built up.

A method is described for operating an actuator adapted to move via a pressurized fluid circuit a valve pin of an injection nozzle for molten material within a mold, wherein the valve pin moves from a closing position, where no molten material passes through the nozzle, to an opening position, where molten material passes through the nozzle, and the actuator comprises a chamber and a piston that is movably mounted in the chamber, linearly displaced by the thrust of the fluid and connected to the valve pin to move it. The valve pin is moved by injecting or extracting a predetermined amount of fluid into/from the chamber.

A production plant includes an injection unit suitable for forming processes, and the injection unit includes a barrel and an injection actuator, a hydraulic system for moving the injection actuator, an safety device configured to output an access signal when access detecting a person accessing the production plant and/or a possibility of a person accessing the production plant, and an electronic control unit to operate the hydraulic system in a production mode and in a safety mode. The control unit is configured to switch from the production mode to the safety mode when the access safety device outputs the access signal, and is configured to operate the hydraulic system in the safety mode such that the hydraulic system at least partially, preferably completely, counteracts an axial movement of the injection actuator caused directly or indirectly by an action of a molding compound present in the barrel on the injection actuator.

A production plant includes an injection unit suitable for forming processes, and the injection unit includes a barrel and an injection actuator, a hydraulic system for moving the injection actuator, an safety device configured to output an access signal when access detecting a person accessing the production plant and/or a possibility of a person accessing the production plant, and an electronic control unit to operate the hydraulic system in a production mode and in a safety mode. The control unit is configured to switch from the production mode to the safety mode when the access safety device outputs the access signal, and is configured to operate the hydraulic system in the safety mode such that the hydraulic system at least partially, preferably completely, counteracts an axial movement of the injection actuator caused directly or indirectly by an action of a molding compound present in the barrel on the injection actuator.