Hyundai HX140L, Manual

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2-36
ARM REGENERATION
The return flow from the arm cylinder rod side is pressurized by self weight of arm and so, returns to
port D4. The pressurized oil returning to port D4 enters the arm regeneration & breaker spool through
the arm holding valve and the arm 1 spool. It is supplied the arm cylinder head through internal
passage. This is called the arm regeneration function.
The amount of regeneration fluid is changed by movement of the arm regeneration spool. A few
fluids after P2 parallel passage is push piston "C" through the notch of arm regeneration spool and
selector spool. At this time, the selector spool is opened by pilot pressure from RCV.
Then, the arm regeneration spool shifts to right side and flow to tank pass increases and regeneration
flow decreases. Therefore, pressure of arm cylinder head increases, then, arm regeneration flow
decreases.
Furthermore, the arm regeneration cut pressure is supplied to the port Pb4 of spring opposite side
and arm regeneration spool is move into the right direction fully. The flow from the arm cylinder rod is
returned to the hydraulic oil tank and regeneration function is not activated. (The return fluid is
maximum condition)
C4
P2 Parallel passage
Piston C
Selector spool
Arm regeneration
cut pilot pressure
Arm regeneration
& breaker spool
P2 Bypass passage
Arm holding valve
Arm 1 spool
Arm summation passage
D4
Arm in
pilot pressure
Pc40
Pb4
Pc42
Load check valve
Tank passage
14W92MC22
Arm regeneration
& breaker spool