ENGINE AR-COMPLETE 2444818 - Caterpillar

Illustration 2 g06032962
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) Valve
(5) Stick drift reduction valve
(6) Main control valve
(9) Passage
(10) Return passage
(11) Return passage
(12) Center bypass passage
(13) Stick I control valve
(15) Load check valve
(16) Check valve
(18) Parallel feeder passage
(19) Check valve
(21) Stick II control valve
(22) Parallel feeder passage
(23) Return line
(27) Pilot control valve (stick and swing)
(28) Idler pump
(29) Drive pump
(30) Pilot pump
(31) Stick regeneration valve
(32) Stick unloading valve
(33) Pilot line
(34) Pilot line
(35) Pilot line
(36) Pilot line
(37) Passage
(38) Pilot line
(39) Pilot line
(40) Pressure reducing valve for boom priority
(41) Pilot line
(42) Passage
(43) Passage
(44) Passage
(45) Check valveThe STICK IN operation contains a regeneration circuit. When the joystick for the stick is moved to the STICK IN position, stick regeneration valve (31) and stick unloading valve (32) 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 drive pump and the idler 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 (27) flows through pilot line (33). The pilot oil flow then divides into several flow paths. Part of the pilot oil flows through pilot line (34) to stick I control valve (13), pilot line (35) and pilot line (36). The pilot oil in pilot line (36) also flows through passage (37) in stick drift reduction valve (5). Part of the pilot oil flows through pilot line (38) to stick regeneration valve (31). The remainder of the pilot oil flows through pilot line (39), the pressure reducing valve for boom priority (40) and pilot line (41) to stick II control valve (21).Since the pilot oil pressure has caused the spool in stick I control valve (13) to shift upward, the oil delivery from the idler pump flows through parallel feeder passage (18), load check valve (15), stick I control valve (13) and passage (9) to line (2).The pilot oil pressure in pilot line (41) has caused the spool in stick II control valve (21) to shift upward. Part of the oil delivery from the drive pump that is in center bypass passage (12) flows through check valve (16) and stick II control valve (21) to passage (42). The remainder of the oil delivery from the drive pump flows through parallel feeder passage (22), check valve (19) and stick II control valve (21) to passage (42). All of the oil delivery from the drive pump in passage (42) flows to line (2) and combines with the oil delivery from the idler pump. The combined pump oil flows to the head end of stick cylinder (1).The return oil from the rod end of the stick cylinder flows through