Arm Regenerative Function - Kubota KX080-4 Workshop Manual

KX080-4, WSM

(3) Arm Regenerative Function

(1) Independent travel valve
section
(2) LS drain plug
(3) Micro-orifice
(4) PLS pressure passage
• When the spool is shifted, the pump pressure PPS flows to cylinder port A1 via the main spool PC notch,
compensator spool C notch, the right load check and the main spool LSC notch.
• The pressure (load pressure) in the load check upstream passage is guided to the PLS pressure passage via the
compensator spool LS pressure guide orifice (13), opening the shuttle poppet and becoming the PLS pressure;
it is then guided to the pump as the PLS signal pressure from the PLS port.
• Part of the flow of oil in the PLS pressure passage passes through the micro-orifice (3) in the LS drain plug (2)
and returns to the tank circuit.
• The pressure PPS in the pump pressure passage is guided to the pump from the independent travel valve's PPS
port as the pump signal pressure.
• Part of the oil flowing back from the actuator flows from cylinder port B2 via the CT notch in the main spool and
the regenerative poppet to the upstream passage of the load check poppet and is combined as a regenerative
flow. And part of the returning oil passes through the arm regenerative sleeve and returns to the tank circuit.
(5) Main spool
(6) Compensator spool
(7) Load check valve
(8) Shuttle valve
(9) Pump pressure passage
(10) Unload spool
(11) Arm regenerative sleeve
(12) Regenerative poppet
3-M20
HYDRAULIC SYSTEM
(13) LS pressure guide orifice
(a) To pump
(b) Regenerative flow
RY9212158HYM0019US0
KiSC issued 08, 2015 A