Komatsu ecot3 PC300LC-8 Shop Manual page 173

10 Structure, function and maintenance standard
2. When the arm is in neutral
Operation
Moves the lever to neutral with the arm
q
dumped.
q Pressurized oil flown inside poppet (5) from
orifice (a) of poppet (5) is closed by pilot piston
(2).
q The holding pressure of arm cylinder head
works on ring-shaped area (S) caused by the
difference between outside diameter (d1) of
poppet (5) and seat diameter (d2) to move it to
the right.
q The sum of this force and the force of spring
(4) closes poppet (5).
q Pressurized oil from the control valve and the
holding pressure of the arm cylinder head are
shut off.
PC300, 350-8
SEN01994-01
47