A method for monitoring the hydraulic supply system of a plastic processing machine. In order to monitor the state of the hydraulic system without great effort, the method includes the following steps: a) Prior to operation of the machine: Determination of the nominal flow rate of a hydraulic pump as a function of an operating parameter of the hydraulic pump and determination of the nominal displacement speed of the hydraulically driven axis when a piston-cylinder element is acted upon by a predetermined nominal flow rate; b) During operation of the machine: When the hydraulically driven axis is operated: measuring the at least one operating parameter of the hydraulic pump as well as the actual displacement speed of the hydraulic axis and comparing the actual displacement speed with the nominal displacement speed resulting from the previously measured operating parameter of the hydraulic pump, and outputting the result of the comparison.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

An actuator system for an injection molding system includes a double acting pressurized fluid actuator having a piston drive movable in a cylinder space, a flow control valve for regulating a flow rate of pressurized fluid to and/or from the cylinder space, a flow sensor for detecting the flow rate of pressurized fluid to and/or from the cylinder space, and an electronic controller for controlling the flow control valve to regulate the flow rate of pressurized fluid to and/or from the cylinder space depending on the flow rate detected by the flow sensor.

In one aspect, there is provided an injection molding system configured to operate in a plurality of cycles. The system comprises, amongst other things, a controller that is configured for performing a comparison of a variable pressure setpoint with a target pressure value. The controller is configured to, when the target pressure value is less than the variable pressure setpoint by at least a predetermined lower bound, (i) decrease the variable pressure setpoint to a reduced variable pressure setpoint and (ii) not further decrease the variable pressure setpoint from the reduced variable pressure setpoint until the pump assembly operates for a plurality of stabilizing cycles at the reduced variable pressure setpoint.

An actuator system for an injection molding system includes a double acting pressurized fluid actuator having a piston drive movable in a cylinder space, a flow control valve for regulating a flow rate of pressurized fluid to and/or from the cylinder space, a flow sensor for detecting the flow rate of pressurized fluid to and/or from the cylinder space, and an electronic controller for controlling the flow control valve to regulate the flow rate of pressurized fluid to and/or from the cylinder space depending on the flow rate detected by the flow sensor.

A hydraulic system for a molding machine with a hydraulic valve, includes an actuator for positioning the hydraulic valve, a machine control system realized separate from the hydraulic valve, a first signal connection between the machine control system and the hydraulic valve, and a sensor. The sensor is signal-connected to the machine control system via a second signal connection, and the machine control system is formed to carry out a valve regulation of the hydraulic valve on the basis of measured values of the sensor.

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.

Injection molding system comprising at least one first actuator-system (D1, D2, D3), the first actuator system comprising: at least one piston drive having at least two pressure line connectors (CP2, CP3) to drive a piston to open or close a molding nozzle, pressure lines (L1, L2) connectable to a changeover valve (V) having a pressure line connector (P) and tank line connector (T) and at least two changeover pressure line connectors, wherein the first changeover valve pressure line connector (CV1) is connectable to a first pressure line (L1) and the second changeover valve pressure line connector (CV2) is connectable to a second pressure line (L2), wherein the second pressure line (L2) is connected to the second pressure line connector (CP2) of the piston drive, an electronically adjustable flow control valve having a first pressure line connector and a second pressure line connector, wherein the first pressure line connector of the adjustable flow control valve being connected to the first pressure line (L1) to allow a connection to the first pressure line connector (CV1) of the changeover valve (V), and the second pressure line connector is connected to a third pressure line (L3) which establishes a connection to the second pressure line connector (CP3) of the piston drive, at least one electronic flow sensor for (P1, P2, P3) sensing flow rate in the first, second and/or third pressure lines (L1, L2, L3), a controller connected to the adjustable flow control valve and to the at least one sensor, configured to electronically adjust the flow control valve, depending on information of the at least one sensor, controlling thereby the timing and the speed of the movement of the piston and the molding nozzle.

The invention relates to a hydraulic device for supplying a plurality of work units (3a, 3b), in particular on a plastics injection moulding machine, said device comprising at least one controller (7), at least one valve regulator and/or one valve controller and a central drive (1). A regulating valve (13a, 13b) with a regulating-valve geometry is provided on at least one of the work units (3a, 3b). Pressure sensors (8) detect at least one pressure both upstream and downstream of the regulating valve (13a, 13b), the load pressure (10a, 10b) of at least one of the work units (3a, 3b), and the system pressure (9). Since the valve regulator and/or the valve controller has knowledge about the regulating-valve geometry of the at least one regulating valve (13a, 13b) and is designed to derive, from a relationship between the regulating-valve geometry and at least one pressure difference resulting from the pressures detected upstream and downstream of the regulating valve (13a, 13b), at least one volume flow rate actual value per regulating valve (13a, 13b), and the controller (7) is designed to derive, from the volume flow rate setpoint values of the at least one work unit (3a, 3b) and/or the volume flow rate actual values of the at least one regulating valve (13a, 13b), at least one setpoint value feedforward control for the central drive (1) in such a way that the system pressure (9) corresponds at least to the relevant highest load pressure (10a, 10b) of the work units (3a, 3b), the hydraulic device is improved in terms of functionality, energy, efficiency and economy.