Event: Rocker Arm Assembly Cylinder - Lowering (Retract)
For previous steps in this sequence see the event “HPU – On.”
The Rocker Arm Assembly with the Top Pinch Roll is raised and lowered by the two Rocker Arm Assembly Cylinders.
1) Directional Control Valve 310.24 is energized to the parallel flow pattern allowing pressurized hydraulic fluid to flow through the valve passing from P to A. Next, the fluid flows freely through the A-port check valve of Pilot Operated Check Valve Module 170.22, then through the A-port check valve of Flow Control Valve Module 177.22 and then into the cap ends of Rocker Arm Assembly Cylinders 813.01 and 813.02, causing the cylinders to extend.
2) Exhaust flow from the rod ends of the cylinders is forced by the B-port check valve of the flow control valve module to flow through the B-port needle valve of the module, thereby achieving meter-out speed control of the extension speed of the cylinders.
3) Next, the exhaust fluid flows freely through the B-port check valve of the pilot operated check valve module, which has been piloted open by pilot pressure from the A-side of the circuit.
4) Finally, the exhaust fluid flows back to tank through the directional control valve, passing from B to T, then back to tank through Duplex Return Line Filter 045.03.