7.
SWING OPERATION LINA R DM RB U C K E T EB O O M C Y E R C Y LIN D E C Y LIN D R T R A V E L M O T O R MUPi2Pi1 P5 RsP4 Pn1 Pn2 PCbc BC1 PDbc NRV2 Cck DR9 BC2 NRV1 Cco Co CoR Bk SH P PD0 Co5 AkR PA 0k o DoR 4PBk AU PG PDo OPTION BUCKET PCbP cAk LCo LCk1 LCk2 DR Ca CaR Da DaR BbkR PBaD PaR L7 CRa R/G PBa2 PCa PAa2 MB MM UA PDa PAa2 ARM1 CcbLCa LCa2 ARM2 PD A0 bR 2 k6 PBa LCar PCsp PBrc PDb2 BOOM2 SWING P/R ARM REGEN DPA Rb 4k LCbk BbR Bb (CW)VB VA(CCW) Ab Cs DR2 PD Cs AbR CRb PbL PBb1P02 P04 s PDs PAb1 DR5 SWING LCs LCb BOOM1 PDb2 P03 DR3 Btr Ctl BtR Atr PD Ctl tl AtR PBtr PDtl PAtr SH Patt ( TR RIG AVH ET L) T(L RE AF VT E) L RCV PEDAL P T TRAVEL PS DR1 V2 P01 PtrPS TS MRV T1 P1 P2 Pu (2) (1) (4) (3) PAtr PBtr PDtl PCtl Dr#, dr# SWING P T ARM BUCKET P T BOOM A2A1 MPILO PT PU M PPU M P PU P03 P Pu (MCV)(T/Joint) (MCV) (1) (3) (2) (4) (3) (1) (2) (4) A B D E F G H J A5 A3 A2 A1 P4 P01(MCV) P3 PG(S/Motor) P2 Psv(Pump) H Y D R A U LIC TA N K a c b d e2 e d1 f g h h1 j h2 P(2-EPPR valve) PS PS PS T PCs PDs PCa PAk PAb1 PBb1 P1 PCsp PS PS LINE FILTER PS PDa PBk 330S3HC15 When the left control lever is pushed left or right, the swing spool in the main control valve is moved to the left or right swing position by the pilot oil pressure from the remote control valve.
Also the swing operation preference function is operated by the pilot pressure PCsp (refer to page 2-51). The oil from the A1 pump flows into the main control valve and then goes to the swing motor. At the same time, the return oil from the swing motor returns to the hydraulic oil tank through the swing spool in the main control valve. When this happens, the upper structure swings to the left or right. The swing parking brake, make up valve and the motor brake valve are provided in the swing motor. The cavitation which will happen to the swing motor is also prevented by the make up valve in the swing motor itself.
3-20 RV2 Cck BC1 BC2 Cco N NRV1 RV2 Cck CoR DoR LCo CaR AkR LCk1 LCk2 BUCKET BbkR ARM2 ARM REGEN Da PBaDR7 CRa PaL PCa PDa ARM1 PAa2 PCsp PDb2 BOOM2 DaR LCa Ccb SWING P/R LCa2 LCar LCbk Cs Ds PCs PDs DR5 SWING P03 DR3 Ctl Dtl PCtl PDtl SH Patt ( TR RIG AVH ET) PS DR1 P01 PtrPS TS LCs BbR AbR LCb BtR AtR CRb BOOM1 L (LEFT) TRAVEL