Event: Upper Pinch Roll Entry Side Cylinder - Retract

For previous sequences in this event see the event “Roll Change HPU – On.”

 

1)    Directional Control Valve 303.15 is energized to the crossover flow pattern allowing pressurized hydraulic fluid to flow through the valve passing from P to B delivering pilot pressure to open Pilot Operated Check Valve 162.06 allowing pressurized hydraulic fluid to flow to the P-port of Directional Control Valve 310.21, which is energized to the parallel flow pattern, flow pattern allowing pressurized hydraulic fluid to flow through the valve passing from P to A.

2)    At the same time the pilot pressure ports of Pilot Operated Check Valves 162.03, 162.04 and 162.05 are vented through 303.15, and those check valves close. When 162.03 is closed, incoming pressurized fluid from the pressure passage of the manifold is prevented from flowing to Proportional Pressure Reducing Valve 278.02 and fluid from Accumulator 236.05 is prevented by 162.05 from flowing to the P-port of Directional Control Valve 310.21. Pilot Operated Check Valve 162.04 prevents fluid from the P-port of 310.21 from flowing toward the accumulator.

3)    Next, the fluid which flowed through 310.21 flows freely through A-port Pilot Operated Check Valve Module 171, then freely through the check valves of Flow Control Valves 182.05 and 182.08 into the rod ends of Entry Side Upper Pinch Roll Cylinders 654.01 and 654.02 causing the cylinders to retract.

4)    Exhaust flow from Entry Side Upper Pinch Roll Cylinder 654.01 is forced to flow through the needle valve of Flow Control Valve 182.06 by the check valve in 182.06. Similarly, exhaust flow from Entry Side Upper Pinch Roll Cylinder 654.02 is forced to flow through the needle valve of Flow Control Valve 182.07 by the check valve in 182.07. Thus meter-out flow control of the retraction speed of the cylinders is achieved.

5)    Next, the exhaust flow from the cylinders combine and flows back to tank, passing through Directional Control Valve 310.21 from B to T, then through Check Valve 122.07 and Duplex Return Line Filter 045.01.