HYDRAULICS – CX130/CX160
5 - 22
CX EXCAVATORS
SWING
Swing Priority
1) A priority circuit assures swing operation when swing and arm is operated at the same
time.
When operating the swing and arm simultaneously as in bank shaving or bank cutting
operation, a priority circuit in the control valve achieves swing priority.
Oil flow from pump2 (rear pump) enters the PL port of the control valve and flow from pump1
(front pump) enters the PR port. When swing right or left is activated pilot pressure is sent
from the swing shuttle valve to the cut valve at port pi2 of the main control valve. This allows
the swing priority valve to remain in the restricted (orifice) position. Which prioritizes pump2
oil for swing over the arm circuit.
During boom up operation pilot pressure is sent to the boom2 spool, which shuts off the open
center passage to the arm1 spool. Pilot pressure is routed from the boom up pilot control
circuit through the cut valve at port pi1 of the main control valve. This shifts the swing priority
valve to the unrestricted position, which assures pump2 oil flow for arm circuit operation.
When swing and arm or boom up is operated at the same time, the swing priority valve
remains in the restricted (orifice) position.
To Next Page
Loading...
