BRACKET 7I3137 - Caterpillar

Illustration 4 g06303921
Hydraulic schematic for BOOM RAISE and STICK IN
(1) Flow combiner PHMV
(2) Boom cylinders
(3) Line (oil flow from boom cylinder rod end)
(4) Line (oil flow to boom cylinder head end)
(5) Main control valve
(6) Flow combiner spool
(7) Passage
(8) Boom independent metering valve (IMV)
(9) Passage
(10) Boom cylinder-to-tank rod end spool
(11) Boom pump-to-cylinder head end spool
(12) Flow compensator
(13) Valve
(14) Boom drift reduction valve
(15) Front pump bypass PHMV
(16) Rear pump bypass PHMV
(17) Stick pump-to-cylinder PHMV
(18) Stick pump-to-cylinder head end spool
(19) Return passage
(20) Stick cylinder
(27) Load check valve
(29) Front pump
(30) Pilot pump
(31) Rear pump
(60) Boom drift reduction solenoid valve
(62) Boom head end cylinder-to-tank PHMV
(63) Boom head end pump-to-cylinder PHMV
(64) Boom rod end pump-to-cylinder PHMV
(65) Boom rod end cylinder-to-tank PHMVDuring combined operations of BOOM RAISE and STICK IN, the ACS control algorithm determines the amount of flow that is required for circuit. Flow distribution is based off inputs such as joystick position and cylinder pressure sensors. Output signals sent to the pump-to-cylinder and cylinder-to-tank spools vary to provide the optimum flow to the circuit which requires the most demand.When the joystick is moved to the BOOM RAISE position during a STICK IN, the ACS valve ECM limits the signal to stick pump-to-cylinder PHMV (17). Stick pump-to-cylinder spool (18) restricts the amount of pump oil that can flow to the head end of stick cylinder (20). An increased amount of oil flow is then sent to the head end of boom cylinders (2) during this combined hydraulic operation.The amount of oil flow from the main pumps to the stick hydraulic circuit decreases. This action causes a greater portion of the oil flow from the main pumps to flow to the head end of the boom cylinders (2).Boom Lower (With Regeneration)
Illustration 5 g06303959
Hydraulic schematic for BOOM LOWER with regeneration
(1) Flow combiner PHMV
(2) Boom cylinders
(3) Line (oil flow from boom cylinder rod end)
(4) Line (oil flow to boom cylinder head end)
(5) Main control valve
(6) Flow combiner spool
(7) Passage
(8) Boom independent metering valve (IMV)
(9) Passage
(10) Boom cylinder-to-tank rod end spool
(11) Boom pump-to-cylinder head end spool
(12) Flow compensator
(13) Valve
(14) Boom drift reduction valve
(15) Front pump bypass PHMV
(16) Rear pump bypass PHMV
(19) Return passage
(27) Load check valve
(29) Front pump
(30) Pilot pump
(31) Rear pump
(60) Boom drift reduction solenoid valve
(62) Boom head end cylinder-to-tank PHMV
(63) Boom head end pump-to-cylinder PHMV
(64) Boom rod end pump-to-cylinder PHMV
(65) Boom rod end cylinder-to-tank PHMVThe boom hydraulic circuit contains a regeneration function. This regeneration function allows the return oil from the head end of the boom cylinders to be supplied to the rod end of the boom cylinders during the BOOM LOWER operation. The regeneration function is accomplished within the boom independent metering valve section (8).The ACS valve ECM uses pressure sensor information to determine when a regeneration function can be accomplished. When the boom cylinder head end pressure is high and the joystick position sensor detects a boom down operation, the boom regeneration function is activated.When the joystick for the boom is moved to the BOOM LOWER position, the ACS valve ECM activates pump-to-cylinder PHMV (64) and