TURBOCHARGER GP 2411700 - Caterpillar

Illustration 1 g01331327
Cab
(1) Joystick (stick and swing)
(2) Joystick (boom and bucket)
Illustration 2 g00800563
Main control valve (top view)
(3) Stick I control valve
(4) Swing control valve
(5) Left travel control valve
(6) Right travel control valve
(7) Boom I control valve
(8) Attachment control valve
(9) Bucket control valve
(10) Swing priority control valve
(11) Stick regeneration control valve
(12) Boom II control valve
(13) Stick II control valve When joystick (1) and/or joystick (2) are operated, the pilot control valves send pilot pump oil through the pilot lines to pilot ports at the main control valve in order to shift the spools in the main control valve. Pilot oil that enters the control valves from the top causes the machine operations in Table 1. Pilot oil that enters the control valves from the bottom causes the machine operations in Table 2.
Table 1
Pilot line Control Valve Machine Operation
(3) Stick I control valve STICK IN
(4) Swing control valve SWING LEFT
(5) Left travel control valve REVERSE LEFT TRAVEL
(6) Right travel control valve REVERSE RIGHT TRAVEL
(7) Boom I control valve BOOM LOWER
(9) Bucket control valve BUCKET CLOSE
(12) Boom II control valve BOOM RAISE
(13) Stick II control valve STICK IN
Table 2
Pilot line Control Valve Machine Operation
(3) Stick I control valve STICK OUT
(4) Swing control valve SWING RIGHT
(5) Left travel control valve FORWARD LEFT TRAVEL
(6) Right travel control valve FORWARD RIGHT TRAVEL
(7) Boom I control valve BOOM RAISE
(9) Bucket control valve BUCKET OPEN
(12) Boom II control valve BOOM LOWER
(13) Stick II control valve STICK OUT
Illustration 3 g01436636
Pilot control valve (stick and swing)
(1) Joystick
(2) Rod
(3) Return passage
(4) Passage
(5) Spool
(6) Plate
(7) Rod
(8) Spring
(9) Seat
(10) Seat
(11) Spring
(12) Spring
(13) Return chamber
(14) Return passage
(15) Passage
(16) Spool
(17) Port (return pressure to valve)
(18) Passage (pilot supply pressure)
(19) Port (reduced pressure to valve)
(20) Port (pilot supply)
(21) Port (tank) When joystick (1) is moved to the right, plate (6) tilts to the right. Plate (6) pushes down on rod (7). Seat (10) moves down against the force of metering spring (11) and spring (12). The force of metering spring (11) shifts spool (16) downward. Passage (15) opens. The pilot oil flows through passage (20), passage (18), passage (15) and port (19) to the main control valve. The pilot oil pressure shifts the spool of the main control valve. This enables the implement operation or swing operation.The return pilot oil at the opposite end of the spool in the main control valve returns to the pilot control valve through port (17). Since rod (2) is not pushed down by plate (6), return passage (3) is open and passage (4) is closed. The return pilot oil flows through return passage (3), return chamber (13) and port (21) to the hydraulic tank.The force of metering spring (11) varies with the position of the joystick. Since spool (16) is moved by the force of metering spring (11), the pilot oil pressure that flows through passage (15) to the main control valve directly corresponds with the position of the joystick. Spool modulation in the main control valve directly corresponds with the amount of movement of the joystick.When the joystick is moved