Rockwell Automation 1771-QDC, D17716.5.93(Passport) PLASTIC MOLDING MODULE - Manual (Page 28)

Overview of Inject, Clamp, and Eject Mode
Chapter 1
1-16
Because system pressure may change from one phase to the next, we
recommend that you:
assign pressure control to phases that require pressure profiles
(and are hydraulically plumbed to support it)
place the system pressure sensor accordingly in the hydraulic circuit
configure the remaining phases with velocity profiles
We define open-loop pressure control as when the QDC module controls
phase pressure without input from the system pressure sensor. For example:
when the system pressure sensor monitors the clamp for closed-loop pressure
control, the QDC module can control:
ram (screw) pressure for pack, hold, and plastication in open loop
ejector velocity in closed- or open-loop using a position sensor
For example:
For this Phase The QDC Module Can Control it With
clamp close and open closedĆloop pressure
injection openĆloop pressureĆlimited velocity
pack/hold openĆloop pressure
plastication openĆloop pressure
ejector advance and retract velocity
In general:
If your system pressure sensor
reads pressure for only ONE of
these modes:
Then you must control the other modes by either of:
1. closedĆ or openĆloop velocity
2. openĆloop pressure
inject clamp, eject
clamp inject , eject
eject inject, clamp
We illustrate three examples of hydraulic circuits compatible with the QDC
module in the inject, clamp, and eject mode:
4-valve system with system pressure sensor
3-valve system with ram (screw) pressure sensor
2-valve system for inject phase with clamp and ejector position inputs
(clamp and ejector direction solenoid valves controlled by ladder logic)
Example Hydraulic Circuits
for the Inject, Clamp, and
Eject Mode