4. TRAVEL SPEED CONTROL SYSTEM ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER R/H L/H REG Dr Ps Ps MU MB MA MB VA(FW) VB(BW) Dr P RCV PEDAL PAtr (2) SWING ARM P T (4) (1) (2) (3) A E D B Psv(Pump) P2 PCsp PAk PDs PCs PCa a b d e f g h j h2 PS d1 c e2 PS PAb1 PBb1 h1 PS T P1 P(2-EPPR valve) PS PS PS PDa PBk LINE FILTER 330S3HC05 When the travel speed solenoid valve was placed in the Hi position, the pressure oil from pilot pump through line filter flows to port Ps of travel speed change over valve, and the control piston is pushed, thus minimizing the displacement.
When the travel speed solenoid valve was placed in the Lo position, the oil of Ps port return to the tank and the control piston is returned, thus maximizing the displacement.
3-10 RV2 Cck Bk Ak P04 PBk PAk BUCKET PCbc BbkR PBa2 PAa2 ARM2 DR6 P02 PBa Abk PBrc ARM REGEN PAbk DR4 DR9 Co P05 Do PCo PDo OPTION Ca BC2 Cco NRV1 CoR AkR LCk1 LCk2 DoR OPTION LCo CaR BUCKET BbkR Da DR7 CRa PaL ARM1 DaR BbkR LCa LCa2 ARM2 PAa2 DR6 Csp Db2 BOOM2 Ccb SWING P/R LCar LCbk BbR ARM REGEN P02 Abk PBrc PAbk DR4 Cs AbR Ds PCs PDs DR5 SWING LCs LCb P03 DR3 Ctl BtR Dtl AtR PCtl PDtl SH Patt ( TR RIG AVH ET L) P T TRAVEL PS DR1 P01 PtrPS TS P1 P2 Pu 1) (4) (3) Btr PDtl PCtl Dr#, dr# BUCKET P T BOOM TRAVEL SPEED SOLENOID VALVE P03 P Pu (MCV) (T/Joint)(MCV) (3) (1) (2) (4) F G H J A5 A3 A2 A1 P4 P01(MCV) P3 PG(S/Motor) Cs Ds PCs PDs DR5 SWING LCs AbR LCb CRb BOOM1 P03 DR3 Ctl Dtl PCtl PDtl Patt (RIGHT) TRAVEL DR1 BtR AtR (RIGHT) TRAVEL (LEFT) TRAVEL BUCKET P T BOOM TRAVEL SPEED SOLENOID VALVE P03 P Pu (MCV) (T/Joint)(MCV) (3) (1) (2) (4) F G H J A5 A3 A2 A1