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| Illustration 1 | g03787910 |
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Hydraulic schematic for STICK OUT (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line (oil flow from stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (7) Stick independent metering valve (IMV) (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (14) Stick pump-to-cylinder head end spool (15) Stick pump-to-cylinder rod end spool (16) Stick cylinder-to-tank rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (19) Main control valve (20) Passage (21) Passage (22) Flow combiner spool (23) Flow combiner PHMV (24) Drive pump bypass PHMV (25) Idler pump bypass PHMV (26) Pilot pump (28) Idler pump (27) Drive pump | |
A STICK OUT operation is accomplished when the oil delivery from both drive pump (27) and idler pump (28) is supplied to the rod end of stick cylinder (1). Flow combiner spool (22) remains in the NEUTRAL position allowing drive pump oil in passage (21) to combine with idler pump oil in passage (20). The combined oil from idler pump (28) and drive pump (27) then flows to stick IMV section (7).
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| Illustration 2 | g03787983 |
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Main control valve (4) Port (stick IN) (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (17) Port (stick OUT) | |
When the joystick for the stick is moved to the full STICK OUT position, the ACS valve ECM activates pump-to-cylinder PHMV (10) and cylinder-to-tank PHMV (8). Pilot oil then shifts spool (13) and spool (15) upward. Simultaneously, the machine ECM activates rear pump bypass PHMV (24) and front pump bypass PHMV (25). Bypass PHMV's (24) and (25) are modulated according to the joystick position. Pump oil is then supplied to passages (21) and passage (20) in main control valve (19).
The oil delivery from idler pump (28) flows through passage (20) in main control valve (19) to stick IMV (7). The oil delivery from drive pump (27) flows through flow combiner spool (22), passage (21), and passage (20) to stick IMV (7).
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| Illustration 3 | g03787912 |
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Stick IMV section (stick OUT) (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line (oil flow from stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (15) Stick pump-to-cylinder rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (20) Passage | |
Pump delivery oil in passage (20) flows through flow compensator (6). Load check valve (12) opens and allows the pump oil to flow to stick pump-to-cylinder spool (15). The pump oil then flows through port (17) and line (2) to the rod end of stick cylinder (1).
Return oil from the head end of stick cylinder (1) flows through line (3) to port (4). Return oil flows through cylinder-to-tank spool (13) and to the hydraulic tank.
Note: For more information on the stick drift reduction valve, refer to Systems Operation, "Stick Drift Reduction Valve".
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| Illustration 4 | g03787913 |
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Hydraulic schematic for STICK IN (with regeneration) (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line (oil flow from stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (7) Stick independent metering valve (IMV) (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (14) Stick pump-to-cylinder head end spool (15) Stick pump-to-cylinder rod end spool (16) Stick cylinder-to-tank rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (19) Main control valve (20) Passage (21) Passage (22) Flow combiner spool (23) Flow combiner PHMV (24) Drive pump bypass PHMV (25) Idler pump bypass PHMV (26) Pilot pump (28) Idler pump (27) Drive pump | |
The stick hydraulic circuit contains a regeneration function. This regeneration function allows the return oil from the rod end of stick cylinder (1) to be supplied to the head end of stick cylinder (1) during the STICK IN operation. The regeneration function is accomplished within the stick independent metering valve section (7).
The ACS valve ECM uses pressure sensor information to determine when a regeneration function can be accomplished. When the stick cylinder rod end pressure is high and the joystick position sensor detects a stick IN operation, the stick regeneration function is activated.
When the joystick for the stick is moved to the STICK IN position, the ACS valve ECM activates pump-to-cylinder PHMV (9) and cylinder-to-tank PHMV (11). The ACS valve ECM also activates pump-to-cylinder PHMV (10). Spool (15) shifts upward allowing return oil from the rod end of the stick cylinder to combine with the oil delivery from idler pump (28) and drive pump (27). This combined oil now flows through spool (14) to the head end of stick cylinder (1).
Since the stick regeneration function supplies return oil from the rod end to the head end of stick cylinder (1), more efficient use of the oil delivery from drive pump (27) and idler pump (28) is achieved during a STICK IN operation.
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| Illustration 5 | g03787916 |
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Stick IMV section (stick IN with regeneration) (1) Stick cylinder (2) Line (oil flow from stick cylinder rod end) (3) Line (oil flow to stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (14) Stick pump-to-cylinder head end spool (15) Stick pump-to-cylinder rod end spool (16) Stick cylinder-to-tank rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (20) Passage | |
Pump delivery oil in passage (20) flows through flow compensator (6). Load check valve (12) opens and allows the pump oil to flow to stick pump-to-cylinder spool (14). The pump oil then flows through port (4) and line (3) to the head end of stick cylinder (1).
Return oil from the rod end of stick cylinder (1) flows through line (2) to port (17). Part of the return oil flows through cylinder-to-tank spool (16) and to the hydraulic tank. Since stick rod end pump-to-cylinder PHMV (10) is activated, spool (15) is shifted upward. The other part of the return oil flows through spool (15) and combines with the oil delivery from drive pump (27) and idler pump (28). The regeneration oil from the rod end of the cylinder is then retuned to the head end of stick cylinder (1).
Stick In (Without Regeneration)
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| Illustration 6 | g03787919 |
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Hydraulic schematic for STICK IN (without regeneration) (1) Stick cylinder (2) Line (oil flow to stick cylinder rod end) (3) Line (oil flow from stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (7) Stick independent metering valve (IMV) (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (14) Stick pump-to-cylinder head end spool (15) Stick pump-to-cylinder rod end spool (16) Stick cylinder-to-tank rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (19) Main control valve (20) Passage (21) Passage (22) Flow combiner spool (23) Flow combiner PHMV (24) Drive pump bypass PHMV (25) Idler pump bypass PHMV (26) Pilot pump (28) Idler pump (27) Drive pump | |
The ACS valve ECM uses pressure sensor information to determine the position of the stick. When the stick cylinder rod end pressure is low and the joystick position sensor detects a stick IN operation, the ACS valve ECM recognizes that the work tool is on the ground and regeneration is not necessary.
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| Illustration 7 | g03787925 |
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Stick IMV section (stick IN without regeneration) (1) Stick cylinder (2) Line (oil flow from stick cylinder rod end) (3) Line (oil flow to stick cylinder head end) (4) Port (stick IN) (5) Pressure sensor (stick cylinder head end) (6) Flow compensator (8) Stick head end cylinder-to-tank PHMV (9) Stick head end pump-to-cylinder PHMV (10) Stick rod end pump-to-cylinder PHMV (11) Stick rod end cylinder-to-tank PHMV (12) Load check valve (13) Stick cylinder-to-tank head end spool (14) Stick pump-to-cylinder head end spool (15) Stick pump-to-cylinder rod end spool (16) Stick cylinder-to-tank rod end spool (17) Port (stick OUT) (18) Pressure sensor (stick cylinder rod end) (20) Passage | |
When the joystick for the stick is moved to the STICK IN position, the ACS valve ECM activates pump-to-cylinder PHMV (9) and cylinder-to-tank PHMV (11). Drive pump (27) and idler pump (28) delivery oil in passage (20) flows through flow compensator (6). Load check valve (12) opens and allows the pump oil to flow to stick pump-to-cylinder spool (14). The pump oil then flows through port (4) and line (3) to the head end of stick cylinder (1).
Return oil from the rod end of stick cylinder (1) flows through line (2) to port (17). The return oil flows through cylinder-to-tank spool (16) and to the hydraulic tank. The stick then moves IN without regeneration oil.