PIPE 0854689 - Caterpillar

Stick In
Illustration 3 g01117792
Hydraulic schematic for STICK IN (fast with regeneration) (1) Stick cylinder (2) Line (oil flow to stick cylinder head end) (3) Line (oil flow from stick cylinder rod end) (4) Pilot line (5) Pilot line (6) Stick drift reduction valve (7) Boom II control valve (8) Valve (9) Passage (10) Passage (11) Stick I control valve (12) Load check valve (13) Center bypass passage (14) Center bypass passage (15) Check valve (16) Stick II control valve (17) Pilot control valve (stick and swing) (18) Shuttle valve (19) Stick regeneration valve (20) Stick unloading valve (21) Return passage (22) Pilot line (23) Pilot line (24) Pilot line (25) Parallel feeder passage (26) Return passage (27) Pilot line (28) Pilot line (29) Line (30) Line (drain) (31) Pressure reducing valve for boom priority (32) Drive pump (33) Idler pump (34) Pilot pump (35) Main control valveThe STICK IN operation contains a regeneration circuit. When the joystick for the stick is moved to the STICK IN position, stick regeneration valve (19) and stick unloading valve (20) are operational in the stick hydraulic circuit. The return oil from the rod end of stick cylinder (1) is supplied to the head end of the stick cylinder. The regeneration circuit makes more effective use of the return oil from the stick cylinder. This allows the oil delivery from the idler pump and the drive pump to perform other implement functions during a STICK IN operation.When the joystick for the stick is moved to the STICK IN position, pilot oil from pilot control valve (17) flows through pilot line (24). The pilot oil flow then divides into several flow paths. Part of the pilot oil flows through pilot line (23) to stick I control valve (11). Part of the oil flows through pilot line (26) into stick drift reduction valve (6). The pilot oil flows into pilot line (4) and pilot line (5). Part of the pilot oil flows through pilot line (5) to stick regeneration valve (19) and to pilot line (22). Pilot line (22) flows through shuttle valve (18) to the pressure reducing valve for boom priority (31) and pilot line (28) to stick II control valve (16). The remainder of the pilot oil flows through pilot line (4) to boom II control valve (7) .Since the pilot oil pressure has caused the spool in stick I control valve (11) to shift upward, the oil delivery from the idler pump flows through center bypass passage (13), load check valve (12), stick I control valve (11) and passage (10) to line (2) .The pilot oil pressure in pilot line (28) has caused the spool in stick II control valve (16) to shift upward. Part of the oil delivery from the drive pump that is in center bypass passage (14) flows through check valve (15) to line (29). The remainder of the oil delivery from the drive pump flows through parallel feeder passage (25) and stick II control valve (16) to line (29).