GROUP 5 COMBINED OPERATION GROUP 5 COMBINED OPERATION 1. OUTLINE 1. OUTLINE ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR ps1 ps2 T3 T1 T2 T4 TRAVEL MOTOR A1 A2 FRONT PUMP REAR PUMP PILOT PUMP HYDRAULIC TANK 480A3HC20 The oil from the A1 and A2 pump flows through the neutral oil passage, bypass oil passage and confluence oil passage in the main control valve. Then the oil goes to each actuator and operates them. Check valves and orifices are located on these oil passage in the main control valve. These control the oil from the main pumps so as to correspond to the operation of each actuator and smooth the combined operation.
STRAIGHT TRAVEL SPOOL STRAIGHT TRAVEL SPOOL This straight travel spool is provided in the main control valve. If any actuator is operated when traveling, the straight travel spool is pushed to the right by the pilot oil pressure (PP) from the pilot pump. Consequently, the left and right travel oil supply passage are connected, and equivalent amount of oil flows into the left and right travel motors. This keeps the straight travel. 3-24 3-24 A5 pb5 ARM 1 pa5 B4 A4 pb4 pa4 A3 B3 pb3 B2 pa3 A2 OPTION BOOM 2 pb2 SWING DR3 pa2 B1 pc6 TRAVEL(LH A1 pb1 pa1 TRAVEL(RH) pr1 STRAIGHT TRAVEL SPOO P1 PSPT PP PA PH PS SWING TRAVEL( RH) TRAVEL(LH STRAIGHT TRAVEL SPOO A6 pb6 pa6 ) TRAVEL STRAIGHT L P3 P2