PLATE 2417716 - Caterpillar

Illustration 1 g03650528
Partial schematic (STICK IN)
(1) Stick cylinder
(2) Stick lowering control valve
(3) Main control valve
(4) Stick lowering PRV STICK OUT Operation
Illustration 2 g03372423
(6) Pilot supply line
(10) Supply line
(12) Drain line
(16) Passage
(19) Passage
(22) Passage
(23) Check valve
(24) Supply port
(25) Spool valve
(26) Drain port
(28) Relief valve When the operator moves the joystick to the STICK OUT position, the pump oil flows from the main control valve through a line to port (10) of the stick lowering control valve. The pump oil flows into passage (16) and the pressure of the pump oil causes check valve (23) to shift downward against the spring. The pump oil flows through passage (16) to passage (19). This action allows pump oil to flow from port (10) to port (24) at the rod end of the stick cylinder. The rod of the stick cylinder will retract in order to move out the stick.When the joystick is returned to the NEUTRAL position, the stick cylinder is held in the OUT position. Check valve (23) and valve (25) prevent the oil in the rod end of the stick cylinder from flowing out of the stick cylinder.STICK IN Operation
Illustration 3 g03373015
(6) Pilot supply line
(10) Supply line
(12) Drain line
(16) Passage
(19) Passage
(22) Passage
(23) Check valve
(24) Supply port
(25) Spool valve
(26) Drain port
(28) Relief valve When the operator moves the joystick to the STICK IN position, pump oil flows from the main control valve through a line that is ported to the head end of the stick cylinder.The oil in the rod end of the stick cylinder begins to flow to port (24) of the stick lowering control valve. As oil flows into passage (19), check valve (23) will remain closed. Simultaneously, pilot oil flow is provided to port (22) of the stick lowering control valve. The pilot oil at port (22) will cause spool (25) to shift to the left. The oil then flows from passage (24) to port (10). From port (10), the oil will flow through a line to the main control valve and back to the hydraulic tank.When the joystick is returned to the NEUTRAL position, the loss of pilot oil pressure will allow the spring to force spool (25) to close. Oil in the rod end of the stick cylinder is trapped and the stick cylinder is held in position.