3-16
When the right control lever is pushed forward, the boom 1 spool in the main control valve is moved
to the down position by the pilot oil pressure from the remote control valve.
The oil from the A2 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 1 spool in the main control valve.
When the down speed of boom is faster, the oil returned from the large chamber of boom cylinder
combines with the oil from the A2 pump, and flows into the small chamber of the cylinder.
This prevents cylinder cavitation by the negative pressure when the A2 pump flow can not match the
boom down speed. And the excessive pressure in the boom cylinder rod side is prevented by the
relief valve.
2. BOOM DOWN OPERATION
RIGHT
LEFT
Pb3
Pd41
B2
Pb1
A1
B1
Pa1
T1
V3
Pd2
Pc2
Pc1
P0
DR0
Pd1
Ai
B4
B5
A5
Pa5
Pb5
Pa4
Pb4
C5
D5
Pc41
Rs
C6
D6
DR4
P03
Patt
P02
Pn2
Pn1
Po5
Puo
P04
DR2
Pc3
Pa20
DR1
DR5
DR3
Pc40
PS
PS
Pi1(Pump)
Pi2(Pump)
BUCKET
CYLINDER
BOOM
CYLINDER
A1
PUMP
A2
PUMP
PILOT
PUMP
HYDRAULIC TANK
RELIEF
VALVE
Pc42
Pb21
Pb20
Pd40
Pd41
Pc40
Pc41
A2
ARM
CYLINDER
DOZER
CYLINDER
TURNING
JOINT
TRAVEL MOTOR
SWING MOTOR
D2
C2
D1
C1
D4
C4
Pa21
Pa20
P04
Pc5
Pd5
Pd6
Pc6
Pu
P1
P2
P3
Pd0
TRAVEL
STRAIGHT
TRAVEL
TRAVEL
BOOM 1
SWING
BOOM 2
ARM 1
OPTION B
OPTION C
(DOZER)
ARM
BUCKET
ARM 2
REGEN
140L3HC11
Содержание HX145 LCR
Страница 11: ...SECTION 1 GENERAL SECTION 1 GENERAL Group 1 Safety Hints 1 1 Group 2 Specifications 1 10...
Страница 204: ...4 5 MEMORANDUM HYUNDAI HEAVY INDUSTRIES CO LTD CONSTRUCTION EQUIPMENT DIV...
Страница 553: ...8 82 Insert O rings to the relief valve 30 and reassemble them to rear cover 20 This completes assembly 17 32038SM42...
Страница 627: ...8 155 125LCR8TM30 Turn casing 1 upside down and remove oil seal 3 using jig 29...
Страница 636: ...8 164 125LCR8TM61 After assembling spring 44 in order clamp plug 41 Tightening torque 5 kgf m 36 lbf ft 31...
Страница 657: ...8 185 8 185 Remove lock nut 22 and then boot 23 14 36078RL14 2507ARL10...
Страница 668: ...8 196 14 15 3 Install cover 3 to body 1 and tighten bolts 14 Torque 10 12 5 kgf m 72 3 90 4 lbf ft 7 21078DA10...