CYLINDER GP-BUCKET 4172659 - Caterpillar

Bucket Open
Illustration 1 g01471832
Hydraulic schematic for BUCKET OPEN (1) Bucket cylinder (2) Main control valve (3) Main relief valve (4) Return passage (5) Parallel feeder passage (6) Line (7) Line relief valve (bucket cylinder head end) (8) Passage (9) Passage (10) Line relief valve (bucket cylinder rod end) (11) Line (12) Bucket control valve (13) Pilot line (14) Pilot line (15) Line (16) Pilot control valve (17) Line (18) Line (19) Line (20) Main pump (21) Pilot pump (22) Pilot Manifold (23) Hydraulic tankDuring a BUCKET OPEN operation, the oil delivery from main pump (20) flows through line (19) to parallel feeder passage (5) in main control valve (2). Oil flows to bucket control valve (12) .Pilot pump (21) supplies oil to pilot control valve (16) through line (15). When the joystick for the bucket is moved to the full BUCKET OPEN position, the pilot oil flows from pilot control valve (16) through pilot line (14). The pilot oil flows to bucket control valve (12) .The pilot oil flow shifts bucket control valve (12) for BUCKET OPEN operation. The oil delivery from the main pump in parallel feeder passage (5) flows through passage (8) through bucket control valve (12). The oil delivery from the main pump then flows through line (11) to the rod end of bucket cylinder (1) .Return oil from the head end of bucket cylinder (1) flows through line (6) to bucket control valve (12). The oil then flows through passage (9) and through return line (17) and line (18) to the hydraulic tank (23) .Bucket Close
During a BUCKET CLOSE operation, the oil delivery from main pump (20) flows through line (19) to parallel feeder passage (5) in main control valve (2). Oil flows to bucket control valve (12) .Pilot pump (21) supplies oil to pilot control valve (16) through line (15). When the joystick for the bucket is moved to the full BUCKET CLOSE position, the pilot oil flows from pilot control valve (16) through pilot line (13). The pilot oil flows to bucket control valve (12) .The pilot oil flow shifts bucket control valve (12) for BUCKET CLOSE operation. The oil delivery from the main pump in parallel feeder passage (5) flows through passage (8) through bucket control valve (12). The oil delivery from the main pump then flows through line (6) to the head end of bucket cylinder (1) .Return oil from the rod end of bucket cylinder (1) flows through line (11) to bucket control valve (12). The oil then flows through passage (9) and through return line (17) and line (18) to the hydraulic tank (23) .