ACCESSORIES MLC165-1 SERVICE/MAINTENANCE MANUAL
10-6
Published 05-26-17, Control # 238-02
Assembly Cylinder (Optional)
Neutral
While drum 3/4 handle is in the neutral position, node 3
receives no out-of-neutral threshold pressure signal from the
drum 3/4 pilot pressure transducer. Node 5 drives no
solenoids in this state, so the valve spool is centered by the
return springs in the neutral position. The center valve
position is closed, so no fluid flows to the cylinder. The
holding valves are also in the closed position, so no fluid can
flow from the rod or barrel end of the cylinder if a load on the
cylinder is producing pressure.
Extend
When the drum 3/4 handle is pushed forward, node 3
receives an out-of-neutral threshold pressure signal from the
drum 3/4 pilot pressure transducer. Node 5 then sends a
24Vdc signal to the assembly cylinder extend solenoid,
energizing it.
The valve spool moves to the open position. Fluid flows from
the pressure port, through the valve, and on to the holding
valve. At the holding valve, fluid flows through the check
valve at the barrel end of the valve and into the barrel end of
the cylinder. At the same time, fluid opens the valve at the
rod end of the cylinder. As fluid fills the barrel end of the
cylinder, the rod extends and the movement forces fluid out
of the rod end, through the open holding valve, through the
open valve, and back to tank.
The accessory system pump pressure command is
proportional to the drum 3/4 handle position. This allows the
assembly cylinder pressure to vary refining the extend or
retract at a controlled speed.
Retract
When the drum 3/4 handle is pulled back, node 3 receives an
out-of-neutral threshold pressure signal from the drum 3/4
pilot pressure transducer. Node 5 then sends a 24Vdc signal
to assembly cylinder retract solenoid, energizing it.
The valve spool moves to the reversing position. Fluid flows
from the pressure port, through the valve, and on to the
holding valve. At the holding valve, fluid flows through the
check valve at the rod end of the valve and into the rod end
of the cylinder. At the same time, fluid opens the valve at the
barrel end of the cylinder. As fluid fills the rod end of the
cylinder, the rod retracts and the movement forces fluid out
of the barrel end, through the open holding valve, through
the open valve, and back to tank.
The accessory system pump pressure command is
proportional to the drum 3/4 handle position. This allows the
assembly cylinder pressure to vary refining the extend or
retract at a controlled speed.
M100838
Figure 10-7. Assembly Cylinder Control
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