Bucket CLOSE
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| Illustration 1 | g01175878 |
(1) Bucket cylinder (2) Swing priority valve (3) Line (4) Line (5) Line (6) Pilot line (7) Control valve (bucket II) (8) Parallel feeder passage (9) Return passage (10) Control valve (bucket) (11) Line (12) Load check valve (13) Load check valve (14) Pilot line (15) Pilot control valve (stick and swing) (16) Parallel feeder passage (17) Pilot line (18) Pilot control valve (boom and bucket) (19) Pilot line (20) Upper pump (21) Lower pump (22) Pilot pump | |
High Speed
Oil from the upper pump and the lower pump is used to extend the bucket cylinder.
When the joystick for the bucket is moved to the BUCKET CLOSE position, pilot oil flows through pilot control valve (18) and pilot line (19) then divides into two paths.
Pilot oil will flow through pilot line (17) to bucket control valve (10). The pilot oil pressure shifts the spool in the bucket control valve. Oil from upper pump (20) will flow through parallel feeder passage (16), load check valve (13), control valve (10), and line (11) .
Pilot oil will also flow through pilot line (14), priority valve (2), and pilot line (6) to control valve (7). The pilot oil pressure shifts the spool in the control valve. Oil from lower pump (21) will flow through parallel feeder passage (8), control valve (7), load check valve (12), and line (4) to line (5) .
The oil flow in line (11) and line (4) will be combined. The oil will flow through line (5) to the head end of bucket cylinder (1). The bucket cylinder will extend.
The return oil from the rod end of the bucket cylinder flows through line (3), control valve (10), and return passage (9) to the hydraulic tank.
Bucket CLOSE during swing
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| Illustration 2 | g01175880 |
(1) Bucket cylinder (2) Swing priority valve (3) Line (4) Line (5) Line (6) Pilot line (7) Control valve (bucket II) (8) Parallel feeder passage (9) Return passage (10) Control valve (bucket) (11) Line (12) Load check valve (13) Load check valve (14) Pilot line (15) Pilot control valve (stick and swing) (16) Parallel feeder passage (17) Pilot line (18) Pilot control valve (boom and bucket) (19) Pilot line (20) Upper pump (21) Lower pump (22) Pilot pump (23) Pilot line (24) Pilot line | |
During a bucket close and a swing operation, only oil from the upper pump is supplied to the bucket cylinder.
When a swing right or a swing left operation is performed, pilot oil flows through pilot control valve (15) to pilot line (23) or pilot line (24). The pilot oil will shift priority valve (2) and the pilot oil in pilot line (14) will be blocked. Control valve (7) will be in the NEUTRAL position.
Oil from upper pump (20) will flow through control valve (10) to the head end of bucket cylinder (1) .
Bucket OPEN
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| Illustration 3 | g01175881 |
(1) Bucket cylinder (2) Swing priority valve (3) Line (5) Line (7) Control valve (bucket II) (9) Return passage (10) Control valve (bucket) (11) Line (13) Load check valve (14) Pilot line (16) Parallel feeder passage (17) Pilot line (18) Pilot control valve (boom and bucket) (20) Upper pump (21) Lower pump (22) Pilot pump (25) Pilot line | |
Oil from the upper pump is used to retract the bucket cylinder.
When the joystick for the bucket is moved to the BUCKET OPEN position, pilot oil flows through pilot control valve (18) and pilot line (25) to bucket control valve (10). The pilot oil pressure shifts the spool in the bucket control valve. Oil from upper pump (20) will flow through parallel feeder passage (16), load check valve (13), control valve (10), and line (3) to the rod end of bucket cylinder (1). The bucket cylinder will retract.
The return oil from the rod end of the bucket cylinder flows through line (11), control valve (10), and return passage (9) to the hydraulic tank.