TERMINAL AS 3T4697 - Caterpillar

Schematic for Stick Hydraulic System
Illustration 1 g00927130
(1) Stick cylinder (2) Line (3) Line (4) Pilot line (5) Pilot line (6) Control valve (7) Line (8) Passage (9) Boom II control valve (10) Return passage (11) Return passage (12) Return passage (13) Center bypass passage (14) Stick II control valve (15) Center bypass passage (16) Load check valve (17) Passage (18) Passage (19) Center bypass passage (20) Passage (21) Passage (22) Valve (regeneration and cut) (23) Stick I control valve (24) Passage (25) Valve (regeneration) (26) Passage (27) Parallel feeder passage (28) Check valve (29) Passage (30) Pilot line (31) Passage (32) Pilot line (33) Pilot line (34) Check valve (35) Pilot line (36) Pilot line (37) Pilot line (38) Shuttle valve (39) Pilot line (40) Shuttle valve (41) Pilot line (42) Solenoid valve (fine control) (43) Upper pump (44) Pilot line (45) Drain line (46) Return line (47) Pilot control valve (stick and swing) (48) Lower pump (49) Pilot pumpStick Control
Introduction
Illustration 2 g00826059
Main control valve (front view) (14) Stick II control valve (23) Stick I control valveWhen the stick is moved to the STICK IN position or the STICK OUT position, control valve (23) and control valve (14) are used. When the control valves are activated, oil from upper pump (43) and lower pump (48) flows to stick cylinder (1) .The stick hydraulic system includes a regeneration circuit that uses regeneration valves (25) and (22). When the control lever is moved to the STICK IN position, the regeneration valves cause oil to flow from the rod end of the stick cylinder to the head end of the stick cylinder. This action allows oil from the main pumps to flow to the other implements.Stick Out
When the control lever is moved to the STICK OUT position, pilot oil (37) from pilot control valve (47) divides into two paths. In one path, the pilot oil flows through pilot line (32) and into stick I control valve (23). The oil shifts the stem of the control valve. When the stem shifts, the lower pump oil in center bypass passage (19) flows through load check valve (16), passage (18), and the stick I control valve. The oil flows next to passage (8), through line (3), and then to the rod end of the stick cylinder.In the other path, pilot oil flows through pilot line (33) and into shuttle valve (40). The oil then flows through pilot line (35) and into stick II control valve (14). The oil shifts the stem of the control valve, and the control valve closes. No oil can flow from center bypass passage (13) through passage (15) to return passage (12) .At the same time, upper pump oil in center bypass passage (13) flows through check valve (28) and passage (29) to line (7). Upper pump oil in parallel feeder passage (27) flows through control valve (14), passage (20), and check valve (34). The oil flows into line (7). All upper pump oil in line (7) flows