Komatsu ecot3 PC300LC-8 Shop Manual page 170

SEN01994-01
2. When the boom is in neutral
Operation
Moves the lever to neutral with the boom
q
raised.
q Pressurized oil flown inside poppet (5) from
orifice (a) of poppet (5) is closed by pilot piston
(2).
q The holding pressure of boom cylinder bottom
works on the 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 boom cylinder bottom
are shut off.
44
10 Structure, function and maintenance standard
PC300, 350-8