3 - 13
When the right control lever is pushed forward, the boom spools in the main control valve are moved
to the lower position by the pilot oil pressure from the remote control valve.
The oil from the front pump flows into the main control valve and then goes to the small chamber of
boom cylinders. At the same time, the oil from the large chamber of boom cylinders returns to the
hydraulic tank through the boom spool in the main control valve.
When the lowering speed of boom is faster, the oil returned from the large chamber of boom cylinder
combines with the oil from the front pump, and flows into the small chamber of the cylinder.
This prevents cylinder cavitation by the negative pressure when the front pump flow can not match
the boom down speed. And the excessive pressure in the boom cylinder rod end circuit is
prevented by the relief valve.
2. BOOM DOWN OPERATION
BOOM2
TRAVEL MOTOR
ARM CYLINDER
BOOM CYLINDER
SWING MOTOR
HYD
TANK
FRONT
PUMP
REAR
PUMP
PILOT
PUMP
P1
P2
R
XBb2
BOOM1
XAb1
dr4
P1
Bb1
XBb1
XBb2
BUCKRT CYLINDER
MAKE UP VALVE
RELIEF VALVE
BOOM HOLDING
VALVE
Summary of Contents for R 160 LC-3
Page 9: ......
Page 142: ...4 4...
Page 182: ...4 44 No of pin Receptacle connector Female Plug connector Male 24 12 24 1 13 S815 024000...
Page 397: ......
Page 398: ......
Page 399: ......
Page 400: ......
Page 401: ......
Page 402: ......
Page 403: ......
Page 404: ......
Page 405: ......
Page 406: ......
Page 407: ......
Page 416: ...8 103 Remove lock nut 21 and then boot 26 15...
Page 427: ...8 114 Install cover 3 to hub 1 and tighten bolts 14 Torque 5 5 12 5kgf m 40 90lbf ft 7 14 15 3...
Page 456: ...8 143 1 STRUCTURE GROUP 11 WORKEQUIPMENT SECTION A SECTION B SECTION C C B B A A C...