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.

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.

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.

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 injection molding apparatus including: a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel and the valve pin being configured or adapted such that the valve pin is movable axially upstream and downstream between an upstream position where the downstream flow of the injection fluid is restricted by a bulbous protrusion (B) of the pin being axially aligned (AL) with the throat (T) of the channel, an intermediate position where downstream flow of injection fluid is unrestricted (WG) and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat.

An injection molding apparatus including: a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel including a throat, downstream flow of the injection fluid being restricted by a bulb portion of the pin, the valve pin having an intermediate position where downstream flow of injection fluid is unrestricted and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat, wherein the actuator is driven by a valve assembly comprised of a spool mechanically driven by first and second actuators or solenoids that each separately engage the spool at opposing axial ends to effect movement of the spool back and forth between the drive fluid flow positions.

An injection molding apparatus including: a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel including a throat, downstream flow of the injection fluid being restricted by a bulb portion of the pin, the valve pin having an intermediate position where downstream flow of injection fluid is unrestricted and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat, wherein the actuator is driven by a valve assembly comprised of a spool mechanically driven by first and second actuators or solenoids that each separately engage the spool at opposing axial ends to effect movement of the spool back and forth between the drive fluid flow positions.

A screw can be driven along an axial direction of a heating barrel and rotatable. An injection piston drives the screw along the axial direction. An injection hydraulic cylinder is partitioned into a first chamber in which pressured hydraulic oil for driving the injection piston is supplied and a second chamber from which hydraulic oil is discharged, and drives the injection piston in the axial direction by hydraulic pressure. A first oil discharge port is blocked by the injection piston when the injection piston advances to a holding pressure switching position. A second oil discharge port can discharge the hydraulic oil from the front chamber regardless of the position of the injection piston. The first oil discharge port is disposed at a position opposed to the first oil discharge port across a center axis of the injection hydraulic cylinder, and is connected to the first oil discharge port.