Stick OUT
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| Illustration 1 | g02162634 |
Hydraulic schematic for STICK OUT (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line(oil flow to boom cylinder head end) (4) Line (pilot oil flow) (5) Line (return pilot oil) (6) Proportional solenoid valve for stick cylinder rod end (7) Main control valve (8) Stick control valve (9) Flow compensator valve (10) Passage (pump delivery flow) (11) Passage (pump delivery flow) (12) Load check valve (13) Passage (oil flow to stick drift reduction / regeneration valve) (14) Stick drift reduction / regeneration valve (15) Valve (16) Proportional solenoid valve for stick cylinder head end (17) Return passage (18) Line (return oil) (19) Pilot manifold (20) Line (pilot oil supply) (21) Pilot pump (22) Front pump (23) Rear pump | |
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| Illustration 2 | g02162939 |
Main control valve (top view from rear of machine) (8) Stick control valve (14) Stick drift reduction / regeneration valve | |
During a STICK OUToperation, stick control valve (8) is activated. The oil delivery from front pump (22) and rear pump (23) are combined in main control valve (7) .
Pilot pump (21) sends pilot system oil through line (20) to pilot manifold (19). The pilot system oil then flows from the pilot manifold to the following components: proportional solenoid valve (6) (stick cylinder head end) and proportional solenoid valve (16) (stick cylinder rod end).
When the stick joystick is operated, an electrical signal from the joystick is sent to the machine ECM. The machine ECM energizes the proportional solenoid valve for stick cylinder rod end (16) .
When the proportional solenoid valve for stick cylinder rod end (16) is energized, the spool in stick control valve (8) shifts. The oil delivery from the main pumps flows from passage (10) through control valve (8), load check valve (12), flow compensator valve (9), bridge passage (11), control valve (8), and passage (13). The oil delivery from the main pumps in passage (13) now flows through stick drift reduction / regeneration valve (14) and line (2) to the rod end of stick cylinder (1). The cylinder rod retracts and the stick extends.
The oil from the head end of stick cylinder (1) flows through line (3), stick control valve (8) and return passage (17) to return line (18). The return oil now flows back to the hydraulic filters and the hydraulic tank.
Stick IN (Slow Without Regeneration)
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| Illustration 3 | g02162819 |
Hydraulic schematic for STICK IN (slow without regeneration) (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line(oil flow to boom cylinder head end) (4) Line (pilot oil flow) (5) Line (return pilot oil) (6) Proportional solenoid valve for stick cylinder rod end (7) Main control valve (8) Stick control valve (9) Flow compensator valve (10) Passage (pump delivery flow) (11) Passage (pump delivery flow) (12) Load check valve (13) Passage (oil flow to stick drift reduction / regeneration valve) (14) Stick drift reduction / regeneration valve (15) Valve (16) Proportional solenoid valve for stick cylinder head end (17) Return passage (18) Line (return oil) (19) Pilot manifold (20) Line (pilot oil supply) (21) Pilot pump (22) Front pump (23) Rear pump | |
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| Illustration 4 | g02164103 |
Stick drift reduction / regeneration valve partial schematic (1) Stick cylinder (2) Line (oil flow from stick cylinder rod end) (3) Line (oil flow to stick cylinder head end) (13) Passage (oil flow to stick reduction / regeneration valve) (14) Stick drift reduction / regeneration valve (15) Valve (24) Solenoid valve (stick drift reduction / regeneration valve) (25) Passage (26) Spool (27) Passage (unloading valve) (28) Unloading valve (29) Return passage (30) Passage (oil flow to the head end of the stick cylinder) (31) Check valve (32) Passage | |
The STICK IN operation is like the STICK OUT operation. The operation of stick drift reduction / regeneration valve (14) during a STICK IN operation is described below.
When the stick joystick is operated in order to perform a STICK IN operation, an electrical signal is sent from the stick joystick to the machine ECM. The machine ECM energizes the proportional solenoid valve for stick cylinder head end (6). The machine ECM also energizes solenoid valve (24) in order to shift spool (26) .
When the proportional solenoid valve for stick cylinder head end (6) is energized, the spool in stick control valve (8) shifts. The oil delivery from the main pumps flows from passage (10) through control valve (8), load check valve (12), flow compensator valve (9), bridge passage (11), and control valve (8). The oil delivery from the main pumps now flows to line (3) and to the head end of stick cylinder (1). The cylinder rod extends and the stick moves IN.
The return oil from the rod end of stick cylinder (1) flows through line (2) to stick drift reduction / regeneration valve (14). Spool (26) is shifted to the right. The oil in the spring cavity on the back side of valve (15) flows through spool (26) to the return system. Return oil from the stick cylinder rod end in line (2) moves valve (15) upward. The oil now flows through passage (13) to the stick control valve and the oil returns to the hydraulic tank and the hydraulic oil cooler. The stick will now move IN.
Stick drift reduction / regeneration valve (14) also contains unloading valve (28). Pressure oil from passage (30) flows through spool (26) to passage (27). The pressure oil in passage (27) shifts unloading valve (28). During a STICK IN operation, unloading valve (28) is in the OPEN position. Part of the return oil from the stick cylinder rod end flows through passage (32), unloading valve (28), return passage (29), passage (17), and return line (18) to the hydraulic tank. The purpose of the unloading valve is to open an additional path for return oil from the rod end of stick cylinder (1) to flow to the return system. Reducing the load on the system reduces the load on the engine.
Note: Unloading valve (28) functions during a STICK IN operation only. When the regeneration condition is active, unloading valve (28) is CLOSED. Once the regeneration condition is inactive, unloading valve (28) is OPENED.
Note: Solenoid valve (24) of the stick drift reduction / regeneration valve receives an electrical signal from the machine ECM for a STICK IN operation only.
Stick IN (With Regeneration)
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| Illustration 5 | g02162874 |
Partial circuit diagram for STICK IN (fast with regeneration) (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line(oil flow to boom cylinder head end) (4) Line (pilot oil flow) (5) Line (return pilot oil) (6) Proportional solenoid valve for stick cylinder rod end (7) Main control valve (8) Stick control valve (9) Flow compensator valve (10) Passage (pump delivery flow) (11) Passage (pump delivery flow) (12) Load check valve (13) Passage (oil flow to stick drift reduction / regeneration valve) (14) Stick drift reduction / regeneration valve (15) Valve (16) Proportional solenoid valve for stick cylinder head end (17) Return passage (18) Line (return oil) (19) Pilot manifold (20) Line (pilot oil supply) (21) Pilot pump (22) Front pump (23) Rear pump | |
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| Illustration 6 | g02164938 |
Stick drift reduction / regeneration valve partial schematic (1) Stick cylinder (2) Line (oil flow from stick cylinder rod end) (3) Line (oil flow to stick cylinder head end) (13) Passage (oil flow to stick reduction / regeneration valve) (14) Stick drift reduction / regeneration valve (15) Valve (24) Solenoid valve (stick drift reduction / regeneration valve) (25) Passage (26) Spool (27) Passage (unloading valve) (28) Unloading valve (30) Passage (oil flow to the head end of the stick cylinder) (31) Check valve (32) Passage (33) Passage | |
When the stick is raised off the ground and is extended OUT past being perpendicular to the ground, trapped oil in the rod end of the stick cylinder is pressurized. The mass and weight of the stick and work tool cause the oil in the rod end of stick cylinder (1) to be pressurized. The STICK IN operation contains a regeneration circuit. When the rod end of stick cylinder (1) is pressurized during a STICK IN operation, regeneration occurs.
When the joystick for the stick is moved to the STICK IN position, the regeneration 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. Regeneration allows the oil delivery from the front pump and the rear pump to perform other implement functions during a STICK IN operation.
When the stick joystick is operated in order to perform a STICK IN operation, an electrical signal is sent from the stick joystick to the machine ECM. The machine ECM energizes the proportional solenoid valve for stick cylinder head end (6). The machine ECM also energizes solenoid valve (24) in order to shift spool (26) .
When the proportional solenoid valve for stick cylinder head end (6) is energized, the spool in stick control valve (8) shifts. The oil delivery from the main pumps flows from passage (10) through control valve (8), load check valve (12), flow compensator valve (9), bridge passage (11), and control valve (8). The oil delivery from the main pumps now flows to line (3) and to the head end of stick cylinder (1) .
The pressurized oil from the rod end of stick cylinder (1) flows through line (2) to stick drift reduction / regeneration valve (14). Spool (26) is shifted to the right. The oil in the spring cavity on the back side of valve (15) flows through spool (26) to the return system. Pressurized oil from the stick cylinder rod end in line (2) moves valve (15) upward. The oil now flows through passage (13) to the stick control valve.
The pressurized oil in passage (13) is restricted by throttling slots in control valve (8) from free-flowing to return passage (17). Pressure oil from passage (13) flows through check valve (31) to spool (26). The pressure oil then enters passage (33) and combines with the pump output oil in passage (30). The pump output oil from passage (30) and the pressure oil from the rod end of the stick cylinder in passage (33) flows to the head end of stick cylinder (1). The stick cylinder extends and the stick moves IN.
Note: Unloading valve (28) remains CLOSED when the regeneration condition is active. The pressure in passage (27) is not high enough to shift unloading valve (28) during regeneration. Pressurized oil in passage (32) is not able to flow through unloading valve (28) .
Note: Solenoid valve (24) of the stick drift reduction / regeneration valve receives an electrical signal from the machine ECM for a STICK IN operation only.
Manual Stick Lowering
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| Illustration 7 | g02163430 |
Manual lowering valve (14) Stick drift reduction / regeneration valve (34) Manual lowering valve (35) Locknut (36) Adjustment screw (37) Check ball (38) Passage (from stick cylinder rod end) (39) Return passage | |
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| Illustration 8 | g02163437 |
Stick drift reduction / regeneration valve schematic (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (14) Stick drift reduction / regeneration valve (15) Valve (26) Spool (34) Valve (manual stick lowering) (38) Passage (from stick cylinder rod end) (39) Return passage | |
When the stick is raised off the ground and is extended OUT past being perpendicular to the ground, oil is trapped in the rod end of stick cylinder (1). The mass and weight of the stick and work tool cause the oil in the rod end of stick cylinder (1) and line (2) to be pressurized. In case the stick cannot be lowered to the ground because of engine problems or hydraulic system problems, the stick can be lowered by opening valve (34) gradually.
Spool (26) in stick drift reduction / regeneration valve (14) is shifted to the left. Pressurized oil in line (2) flows through spool (26) and enters the spring cavity on the back side of valve (15). Valve (15) blocks the flow of pressurized oil in line (2) from flowing to the stick control valve. Opening manual stick lowering valve (34) causes the pressurized oil in line (2) and passage (38) to be routed to return passage (39). The pressurized oil in line (2) lowers and the stick moves IN.
Note: Once the stick is perpendicular to the ground, pressure is no longer created by the mass of the stick and work tool. The stick will rest in the perpendicular position.
In order to manually lower the stick, loosen locknut (35) and turn adjustment screw (36) counterclockwise. Turning adjustment screw (36) countercolockwise allows check ball (37) to OPEN. Once check ball (37) opens, the high-pressure oil in passage (38) can flow to return passage (39). The stick lowers.
Once the stick is perpendicular to the ground, turn adjustment screw (36) clockwise until check ball (37) is CLOSED. Tighten locknut (35) .