Event: Backup Keeper Plates Cylinders, Bottom - Open (Retract)

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

 

Note that this event describes the sequences for Mill Stand F1. The same sequences apply for stand F2 through F6, though the component numbers will change. Refer to the relevant schematic for each stand for the appropriate component number.

 

1)    Directional Control Valve 302.02 is energized to the crossover flow pattern allowing pressurized hydraulic fluid to flow through the valve passing from P to B. Next, the fluid flows freely through the B-port check valve of Dual Pilot Operated Check Valve 172.02, then freely through the B-port check valve of Dual Flow Control Valve Module 179.02 and into the rod ends of Backup Keeper Plates Entry Side Bottom Cylinder 607.03 and Backup Keeper Plates Delivery Side Bottom Cylinder 607.04, causing the cylinders to retract.

2)    Exhaust fluid from the cap ends of the cylinders is forced by the A-port check valve of the flow control module to flow through the A-port needle valve of the module, thereby achieving meter-out speed control of the retraction speed of the cylinders.

3)    Next, the exhaust fluid flows freely through the A-port check valve of the pilot operated check valve module, which has been piloted open by pilot pressure from the B-side of the circuit. Finally, the exhaust fluid flows back to tank through the directional control valve, passing from A to T, Check Valve 122.01 and Duplex Return Line Filter 045.01.