ACCUMULATOR 1228637 - Caterpillar

Bucket Close
Illustration 1 g06142579
Hydraulic schematic for BUCKET CLOSE
(1) Main control valve
(2) Pilot line
(3) Bucket cylinder
(4) Line
(5) Line
(6) Passage
(7) Passage
(8) Bucket control valve
(9) Passage
(10) Check valve
(11) Passage
(12) Return passage
(13) Parallel feeder passage
(14) Pilot control valve
(15) Pilot line
(16) Return line
(17) Idler pump
(18) Pilot pump
(19) Drive pump
(20) Swing brake solenoid valve
(21) Pressure sensor (implement)
Illustration 2 g03030118
Main control valve
(8) Bucket control valveThe oil delivery from drive pump (19) flows through parallel feeder passage (13) in main control valve (1) to bucket control valve (8). The bucket control valve does not utilize the output flow from idler pump (17).When the joystick for the bucket is moved to the BUCKET CLOSE position, the pilot oil flows from pilot pump (18) through pilot control valve (14) to pilot line (2). The pilot oil flows through pilot line (2) to bucket control valve (8). Pilot oil shifts the spool of bucket control valve (8) downward.When the bucket control valve is shifted downward, the oil flow from drive pump (19) in parallel feeder passage (13) flows through passage (11) to check valve (10). The oil flows through check valve (10), through passage (9), and to bucket control valve (8). The oil flows through bucket control valve (8), through passage (6), and through line (5) to the head end of bucket cylinder (3). The oil extends the cylinder rod of bucket cylinder (3). The bucket closes.Return oil from the rod end of cylinder (3) flows through line (4) and passage (7) to bucket control valve (8). The oil flows from the bucket control valve through return passage (12) and through return line (16) back to the hydraulic tank.Bucket Open
The BUCKET OPEN operation is similar to the BUCKET CLOSE operation.The oil delivery from drive pump (19) flows through parallel feeder passage (13) in main control valve (1) to bucket control valve (8). The bucket control valve does not utilize the output flow from idler pump (17).When the joystick for the bucket is moved to the BUCKET OPEN position, the pilot oil flows from pilot pump (18) through pilot control valve (14) to pilot line (15). The pilot oil flows through pilot line (15) to bucket control valve (8). Pilot oil shifts the spool of bucket control valve (8) upward.When the bucket control valve is shifted upward, the oil flow from drive pump (19) in parallel feeder passage (13) flows through passage (11) to check valve (10). The oil flows through check valve (10), through passage (9), and to bucket control valve (8). The oil flows through bucket control valve (8), through passage (7), and through line (4) to the rod end of bucket cylinder (3). The oil retracts the cylinder rod of bucket cylinder (3). The bucket opens.Return oil from the head end of cylinder (3) flows through line (5) and passage (6) to bucket control valve (8). The oil flows from the bucket control valve through return passage (12) and through return line (16) back to the hydraulic tank.Implement pressure sensor
The implement pressure sensor sends an input signal to the