Open Center Load Sensing Control Komatsu Electric Control

1. E-OLSSSection 3.4
E-OLSS: Electronic ControlE-OLSS: Electronic Control
Section 3.4Section 3.4

2. E-OLSSSection 3.4
E-OLSS: Electronic Control
Pump Controller.
The controller receives the input signals, processed these internally and sends
output signals to the TVC solenoid and ON/OFF solenoids.
Electrical Connector
Blocks

3. E-OLSSSection 3.4
E-OLSS: Electronic Control
Input and Output Signals

4. E-OLSSSection 3.4
E-OLSS: Electronic Control
Electronic – OLSS
(Pump Control System)
When load on the pump rises and the
pressure rises, the pump
discharge amount is reduced and
the engine speed is controlled so
that it becomes close to the rated
speed.
Inputs
1. Monitor panel.
2. Speed sensor.
3. Fuel throttle.
4. PPC pressure switches.
5. Engine controller
Outputs
1. TVC solenoid

5. E-OLSSSection 3.4
E-OLSS: Electronic Control
Working Mode Selection
The combination of the 4 level working mode
and 3 level power set makes it possible to
choose a pump absorption torque
corresponding to the nature of the work, so it
is possible to use the engine more effectively
while also reducing fuel consumption

6. E-OLSSSection 3.4
E-OLSS: Electronic Control
PEMC System
(Pump and Engine Mutual
Control System)
The PEMC system has total
control over the pump and
engine outputs.
To give a higher level of both
power and fuel economy.

7. E-OLSSSection 3.4
E-OLSS: Electronic Control
TVC and Swing Lock Prolix
Switches
If there is a failure in the pump
controller, the Prolix Switches can
be switch on to by-pass the
controller. They can be activated
individually.
When the prolix switch to the TVC
solenoid is on, a current is
supplied through a resistor, the
signal becomes constant so the
force pushing the TVC valve is
constant. There is no pump
sensing.
The swing lock solenoid will
receive a constant current, this will
release the swing brake all the
time.

8. E-OLSSSection 3.4
E-OLSS: Electronic Control
Prolix Switch ON
If there is a failure in the
pump controller, the Prolix
Switch can be switch ON to
switch to the resistor side,
by pass the controller.
When this is done the pump
absorption becomes
constant.
The TVC output is controlled
by the (Pe) pressure.
There is no pump sensing.

9. E-OLSSSection 3.4
E-OLSS: Electronic Control
Travel Speed Selector
Function.
To maintain the draw bar pull when
traveling the Cut Off is canceled and main
relief is raised .
Travel speed is selected on the monitor
panel. When high speed is selected the
controller will energize the Travel Speed
Solenoid Valve.

10. E-OLSSSection 3.4
E-OLSS: Electronic Control
Swing Control
Function.
Swing lock brake is applied
when not swinging this
prevents drift.
When the swing lever is
operated the PPC pressure
switch sends a signal to the
controller that swing is in use.
Controller will release the
swing brake by sending a
current to the Swing Parking
Brake Solenoid valve.
Hydraulic release the park
brake actuator.
If an abnormality should occur
in the controller the swing
brake can be released by the
Swing Lock Prolix switch.
When the Swing Lock Prolix
switch is on the swing brake is
not canceled.

11. E-OLSSSection 3.4
E-OLSS: Electronic Control
Text

12. E-OLSSSection 3.4
E-OLSS: Electronic Control
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E – OLSS:E – OLSS:
Electronic ControlElectronic Control