5.
MAIN RELIEF PRESSURE CHANGE SYSTEM ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER TRAVEL MOTOR PCbc P5 P4 Pi2 Rs MU Pi1 Pn1 Pn2 PDbc DR9 Co P05 PDo PCo Do Ca Da PCa PBa DR7 PaL CRa Auto power boost SWING MOTOR PDa PAa2 PBa PDb2 PCsp PDs PCs Cs Ds PAb1 P02 P04 DR5 PDb2 PCtl Dtl DR3 Ctl P03 SH PDtl Patt RCV PEDAL P T TRAVEL PS Ptr P01 DR1 PS TS TS MRV T1 P1 P2 Pu (4) (1) (2) (3) SWING ARM BUCKET BOOM P T PAtr PCtl PDtl PBtr P T Dr#, dr# POWER BOOST SOLENOID VALVE A2 PUMP A1 PUMP PILOT PUMP P03 (MCV) P (T/Joint) Pu (MCV) (4) (1) (2) (3) A H G F E D B J (4) (1) (2) (3) A5 A1 A2 A3 P4 P01(MCV) a b d e f g h j h2 PS d1 c e2 h1 PS Psv(Pump) P3 P2 PG(S/Motor) P(2-EPPR valve) HYDRAULIC TANK PCsp PAk PDs PCs PCa PS PS PS PAb1 PBb1 T P1 LINE FILTER PS PDa PBk 330S3HC06 When the power boost switch on the left control lever is pushed ON, the power boost solenoid valve is actuated, the discharged oil from the pilot pump flows into Pu port of the main relief valve of main control valve; then the setting pressure of the main relief valve is raised from 350 kgf/cm 2 (4980 psi) to 380 kgf/cm 2 (5400 psi ) for increasing the digging power.
And even when pressed switch continuously, it is canceled after 8 seconds. When the auto power boost function is selected to enable on the cluster, the pressure of the main relief pressure is automatically increased to 380 kgf/cm 2 as working condition by the MCU. It is operated max 8 seconds. 3-11 BC1 NRV2 Cck BC2 NRV1 Cco CoR DoR AkR LCk1 LCk2 ION LCo CaR BUCKET BbkR DaR M1 LCa BbkR LCa2 ARM2 PAa2 DR6 Ccb M2 SWING P/R LCar LCbk BbR ARM REGEN P02 Abk PBrc PAbk DR4 Swing reducing spool ING LCs AbR LCb CRb BOOM1 BtR AtR HT) VEL (LEFT) TRAVEL