User Manual

Bosch Rexroth AG
RE 95 320/06.06
DRC Travel Drive Control
13/20
Evaluation
Direction
switch
Control of
variable pump
Accel. pedal
Inch pedal
Control of
variable motors
Time rampsTravel behavior
Pre-position Time ramps
Diesel engine speed
Diesel temperature
Output speed
• Load limiting control
• Overheating pro-
tection
•
Diesel protection
• Speed limiting
Travel behavior
("soft", "medium", "hard")
Evaluation
Teach curve
Inch function
Figure 7: Method of operation of the DRC travel drive control, variants D-E (DRCD and DRCE)
Travel behavior
Travel behavior is controlled by the following variables.
• The travel mode ("soft", "medium", "hard") is defi ned with
one switch and two digital inputs. This determines, among
other properties, how quickly the control of the proportional
outputs is changed.
• The setpoint value for the pump and motor is specifi ed by
the acceleration pedal and the teach curve. The direction is
specifi ed by the direction switch.
• The control of the variable pump for the specifi ed diesel-
engine-speed setpoint value is defi ned in the travel behavior
characteristic.
A separate characteristic with the corresponding ramps can
be parameterized for each travel mode ("soft", "medium",
"hard").
• The output speed at the hydraulic motor and the acceleration
pedal defi ne the behavior of the variable motors.
If the acceleration pedal is pressed:
• If a fi xed displacement motor is connected (only the
variable pump is controlled), the current value of the pump
control increases.
The current value increases with increasing defl ection of the
acceleration pedal. The pump swivels out further and the
vehicle speed increases.
The fi xed displacement motor reaches its maximum speed at
maximum pump fl ow.
• If a variable motor is connected (both variable pump as
well as variable motors are controlled):
With increasing defl ection of the acceleration pedal,
the swivel angle of the pump is initially increased. If the
pump is completely swiveled out, the swivel angle of the
variable motor is also reduced and, as a result, so too is the
displacement. The variable motor is guided by the measured
output speed (hydraulic-motor speed-guided behavior). The
output speed continues to increase.
With the acceleration pedal fully pushed down, the pump
control is at a maximum and the motor is swiveled back to
a minimum displacement V
g min
determined by the hydraulic
travel drive control. The variable motor has reached the
maximum output speed.
The travel behavior is defi ned via two switched inputs. The
selected travel mode determines:
• The characteristic for the travel behavior
• The characteristic for the pre-position
• The reaction behavior during reversing