Gradall XL4000, Manual

Page: 57 / 327

XL 4100/5100 HYrDARAULIC SYSTEM OPERATIONS MANUAL Form No. 29703
Tilt Control Valve
The tilt valve consists of two port reliefs and a section compensator.
See Figure 63
The spool shifts using
electrically triggered end caps. Proportional solenoids on each end cap receive pilot fluid from the pilot feed line.
Pilot fluid then flows to the end cover of the control valve assembly. The reservoir return for the end caps and
solenoid also uses the control valve end cover. When the front end cap solenoid is energized, it opens to direct
pilot fluid to the front end cap (fluid will flow from the front port). When the tilt switch on the right-hand
joystick is actuated, the electrical signal shifts the solenoid spool which sends a pilot signal that shifts the valve
spool. The compensator meters fluid to the spool which then routes fluid to the tilt motor. The valve load sense
system controls compensator shift and signals the pump load sense system. Tilt speed is controlled by the valve
spool metering returning fluid from the motor, and by setting the tilt speed switch in the cab
(see XL
4000/5O00 Upperstructure Mechanical Adjustment & Repair Manual
(Form 29604). When the circuit stalls
while tilting, relief valves open to protect from excessive pressure. The valve spool’s maximum flow rate out of
both work ports is 16 GPM.
FIGURE 63
TILT VALVE SECTION
XVI. Tilt Circuit
(continued)
55
“B” Port
Spool
“A” Port
Port Relief
Electric
Solenoid
End Cap
Port Relief
Compensator