Steer; Interlocks - JLG TOUCAN 10E Service And Maintenance Manual

SECTION 3 - THEORY OF OPERATION

Steer

Steering is actuated by a double acting hydraulic cylinder.
To change steering angle of the wheels, pressure is
applied to one side of the piston and drained from the
other.
To steer to the right, the solenoids of both the steer and
the flow directional valve energize, an appropriate electric
signal is sent to the proportional relief valve and the pump
is run.
To steer to the left, the solenoid of the steer valve ener-
gizes, an appropriate electric signal is sent to the propor-
tional relief valve and the pump is run.
The pump speed, and thereby the rate of steering angle
change, is adjusted based on drive speed. This adjust-
ment is modified by steer personality settings.
Figure 3-7. Steer System - Basic Schematic
The steering sensor is located on the front steering axle. It
is key operated by the right spindle attach pin. There is a
position sensing element and a signal conditioning cir-
cuitry in it to generate the position signal (i.e. the wheel
steering angle). It is powered by 4.3 VDC supplied from
the master power module.
When the wheels are fully steered to the right, is will out-
put approximately 0.7 VDC.
When the wheels are fully steered to the left, it will output
approximately 3.7 VDC.
When the wheels are straight, it will output approximately
2.5 VDC.
Depending on output signal, the speed of the inner drive
motor will be reduced to allow machine to take a curve
(like a differential system).
3-6

Interlocks

Interlocks are system inputs (limit switches, sensors or
internal controller measurement) which affect the system
functions.
NOTE: For more detailed information concerning system
adjustment and operation, refer to section 8 Control
Components.
Overload Switch
The overload switch senses platform load. In order to
avoid false trip, the switch input is delayed.
• The switch must be tripped for more than 3s to con-
sider the platform overloaded.
• The switch must be released for more than 5s to con-
sider the platform not overloaded.
When the platform overloaded:
• All the movements are cut out from both the platform
console and the ground console if the MACHINE
SETUP , LOAD is set to CUTOUT ALL;
• All the movements are cut out from the platform con-
sole if the MACHINE SETUP , LOAD is set to CUTOUT
PLATFORM;
• All the movements can be performed at normal speed
i f t h e M A C H I N E S E T U P, LO A D i s s e t t o N O T
INSTALLED;
Tilt Switch
The tilt switch senses the chassis tilt angle. In order to
avoid false trip, the switch is internally delayed:
• The switch must be tripped for more than 1s to con-
sider the machine tilted.
When the platform is in transport position (none of the
mast switches is tripped), a visual alarm is displayed in
case of machine tilted but the functions are not affected.
When the machine is tilted and out of transport position:
• The drive functions are cut out;
• Jib Lift Up, Mast Lift Up and Swing are allowed at
reduced speed;
• Jib Lift Down and Mast Lift Down are allowed at normal
speed.
Chain Slack Switch
The chain slack switches sense the lifting chains tension.
In case of slack chain detected:
• The drive functions are cut out;
• Jib Lift Down, Mast Lift Down and Swing are cut out;
• Mast Lift Up is allowed at reduced speed;
• Jib Lift Up is allowed at normal speed.
Drive Orientation Switch
The drive orientation switch is a proximity switch which
trips when the turntable is swung ±45° off center of the
normal driving position. This occurs roughly when the jib
is swung past the rear tires. When the drive orientation
switch is tripped:
– JLG Lift – 31210090