3-15
3-15
When the RH 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 boom 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 end circuit is prevented by
the relief valve.
2. BOOM DOWN OPERATION
PS
(P4)
(P3)
N2
Pca
Dr3
P2c2
Ba
Aa
PAa
PBa
Bo
Ao
PAo
PBo
(Ck2)
Drb
PBb2
PSp
Dra
Bs
As
PAs
PBs
Dr4
Pns
Br
Ar
PAr
PBr
TRAVEL(RH)
SWING
BOOM 2
T1
Pa
P2
P1 P1g
P2g
R4
(PTb)
PS
PL1
Py
PBL
PAL
PBb
PAb
Ab
Bb
P2c1
Dr3'
PBc
PAc
PAcs
Bc
Ac
PBa2
PAa2
Pcb
N1
OPTION
ARM 1
ARM 2
BUCKET
BOOM 1
TRAVEL(LH)
SH
Relief valve
HYDRAULIC TANK
TRAVEL MOTOR
SWING MOTOR
ARM
CYLINDER
BUCKET
CYLINDER
BOOM
CYLINDER
PILOT
PUMP
BL
AL
Px
P
R3
PUMP
A1
PUMP
A2
380L3HC11
Содержание HX430L
Страница 11: ...SECTION 1 GENERAL Group 1 Safety Hints 1 1 Group 2 Specifications 1 10 ...
Страница 161: ...4 6 MEMORANDUM HYUNDAI HEAVY INDUSTRIES CO LTD CONSTRUCTION EQUIPMENT DIV ...
Страница 205: ...4 50 No of pin Receptacle connector female Plug connector male 14 1 7 6 14 MG610406 KET SDL CONNECTOR 13 ...
Страница 528: ...8 88 Assemble relief valve assy 45 using torque wrench ÂTightening torque 26Ü2 6 kgfÂm 188Ü18 8 lbfÂft 31 43098TM95 ...
Страница 548: ...8 108 Remove lock nut 22 and then boot 23 14 36078RL14 2507ARL10 ...
Страница 559: ...8 119 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 ...
Страница 589: ...8 149 1 STRUCTURE GROUP 11 WORK EQUIPMENT B SECTION C SECTION B SECTION A C C A B A 21078DA 44 ...