Stick Out
 | |
| Illustration 1 | g01621102 |
Hydraulic schematic for STICK OUT (1) Stick cylinder (2) Passage (3) Check valve (4) Stick lowering control valve (5) Pilot control valve (boom) (6) Return passage (7) Passage (8) Passage (9) Passage (10) Stick I control valve (11) Load check valve (12) Center bypass passage (13) Main control valve (14) Center bypass passage (15) Stick II control valve (16) Check valve (17) Passage (18) Passage (19) Pilot line (20) Parallel feeder passage (21) Return passage (22) Pilot line (23) Line (24) Pilot line (25) Pilot line (26) Pressure reducing valve (boom priority) (27) Return line (28) Drive pump (29) Idler pump (30) Pilot line (31) Selection valve (STICK IN) | |
 | |
| Illustration 2 | g01621224 |
Main control valve (10) Stick I control valve (15) Stick II control valve | |
When the stick hydraulic circuit is operated independently of other hydraulic circuits, stick I control valve (10) and stick II control valve (15) are operational for the STICK OUT operation. When the stick I control valve and the stick II control valve are operated, the oil delivery from idler pump (29) and drive pump (28) is combined. The oil delivery from both pumps flows to stick cylinder (1) in order to perform a stick operation.
The oil delivery from drive pump (28) flows through parallel feeder passage (20) in main control valve (13) to stick II control valve (15). The oil delivery from idler pump (29) flows through center bypass passage (12) in main control valve (13) to stick I control valve (10) .
When the joystick for the stick is moved to the STICK OUT position, the pilot oil flows from pilot control valve (5) through pilot line (24). The pilot oil flow then divides into two flow paths. Part of the pilot oil flows through pilot line (30) to stick I control valve (10) in main control valve (13). The remainder of the pilot oil flows to pressure reducing valve (26), and pilot line (22) to stick II control valve (15) in the main control valve.
The pilot oil in pilot line (30) shifts the spool of stick I control valve (10). The oil delivery from idler pump (29) that is in center bypass passage (12) flows through load check valve (11), passage (8), and passage (7) to stick lowering control valve (4). The oil delivery from the idler pump then flows through load check valve (3), and passage (2) to the head end of stick cylinder (1) .
The pilot oil in pilot line (22) shifts the spool of stick II control valve (15). The oil delivery from drive pump (28) in center bypass passage (14) cannot flow through stick II control valve (15). Part of the oil delivery from center bypass passage (14) flows through a check valve to line (23). The remainder of the oil delivery from the drive pump flows through parallel feeder passage (20) and through check valve (16). The oil then flows to line (23). All of the oil delivery from the drive pump in line (23) combines with the oil delivery from the idler pump. The combined pump oil flows to the head end of stick cylinder (1). This combined pump oil causes the cylinder to extend at an increased rate of speed.
Return oil from the rod end of the stick cylinder flows through return passage (6) to stick I control valve (10). The return oil then flows through return line (27) to the hydraulic tank.
Selection valve (31) can be activated in order to reduce the amount of pump flow to the stick cylinder during a STICK OUT operation. This will provide the appropriate speed to the stick cylinder.
Stick In
 | |
| Illustration 3 | g01621247 |
Hydraulic schematic for STICK IN (1) Stick cylinder (2) Passage (3) Check valve (4) Stick lowering control valve (5) Pilot control valve (boom) (6) Return passage (7) Passage (8) Passage (9) Passage (10) Stick I control valve (11) Load check valve (12) Center bypass passage (13) Main control valve (14) Center bypass passage (15) Stick II control valve (16) Check valve (17) Passage (18) Passage (19) Pilot line (20) Parallel feeder passage (21) Return passage (22) Pilot line (23) Line (24) Pilot line (25) Pilot line (26) Pressure reducing valve (boom priority) (27) Return line (28) Drive pump (29) Idler pump (30) Pilot line (31) Selection valve (STICK IN) (32) Valve (33) Passage (34) Return line (35) Pilot line | |
When the joystick for the stick is moved to the STICK IN position, pilot oil from pilot control valve (5) flows through pilot line (36). The pilot oil flow then divides into several flow paths. Part of the pilot oil flows through pilot line (19) to stick I control valve (10). The pilot oil in pilot line (35) flows to stick lowering control valve (4). Stick lowering control valve (32) shifts.
Note: The stick regeneration valve does not function for the UHD models.
Note: Stick II control valve (15) is not functional for a STICK IN operation. The oil delivery from the drive pump flows through center bypass passage (14) to the hydraulic tank and the negative flow control line. The drive pump will remain at standby pressure.
Since the pilot oil pressure has caused the spool in stick I control valve (10) to shift upward, the oil delivery from the idler pump flows through center bypass passage (12), load check valve (11), stick I control valve (10), passage (9), and passage (6) to the rod end of stick cylinder (1) .
The return oil from the head end of the stick cylinder flows through stick lowering control valve (4). Pilot oil pressure from line (35) opens valve (32) in the stick lowering control valve. The return oil flows through passage (33) and return line (34) to the hydraulic tank.