Komatsu Galeo PC138US-8 Shop Manual page 231

10 Structure, function and maintenance standard
2. When pressurized oil flows from the main
valve to the cylinder
When the piping is free of breakage
Pressurized oil led to chamber (a) from the
q
control valve becomes higher than the com-
bined force of pressure from work equipment
cylinder circuit chamber (b) and spring (6).
Check valve (5) opens and chambers (a) and
q
(b) are interconnected.
Pressurized oil flows from the control valve to
q
the work equipment cylinder.
If the piping is bursted
If piping (A) between the control valve and the
q
work equipment cylinder is broken, pressur-
ized oil in chamber (a) flows outside from the
damaged portion.
Pressure force in chamber (a) drops.
q
Pressure force in chamber (a) drops lower than
q
the combined pressure force of chamber (b)
and spring (6).
Check valve (5) closes and chambers (a) and
q
(b) are cut off.
Pressure for the work equipment cylinder is
q
held to prevent a sudden drop of the work
equipment.
PC138US, USLC-8
SEN02550-01
49