Page 34 - Mechatronics with Experiments

JWST499-Cetinkunt
JWST499-c01
20 MECHATRONICS Printer: Yet to Come October 9, 2014 7:39 254mm×178mm
System components

High-pressure oil manifold
High pressure
oil pump

HEUI
Fuel return line

RPCV
Fuel
filter
Fuel
ECM
Oil pump transfer
pump

Oil Oil
filter cooler Oil Fuel
sump tank
FIGURE 1.19: An example of an electronically controlled fuel injection system used in diesel
engines: HEUI fuel injection system by Caterpillar Inc and Navistar Inc.

used as the amplifier stage between the solenoid signal and injection force. Notice that the
main components of the fuel delivery system are
1. fuel tank,
2. fuel filter,
3. fuel pump,
4. pressure regulator valve,
5. high pressure oil pump,
6. fuel injectors.
The fuel pump maintains a constant fuel pressure line for the injectors. In common-
rail (CR) and electronic unit injector (EUI) type fuel injection systems (such as the hydraulic
electronic unit injector (HEUI) by Caterpillar and Navistar Inc), a high pressure oil pump
in conjunction with a pressure regulating valve is used to provide the high pressure oil line
to act as an amplifier line for the injectors. Hydraulic oil is the same oil used for engine
lubrication. The injectors are controlled by the low power solenoid signals coming from
the electronic control module (ECM). The motion of the solenoid plunger is amplified by
the high pressure oil line to provide the higher power levels needed for the fuel injector.
There are four different fluids involved in any internal combustion engine:
1. fuel for combustion,
2. air for combustion and cooling,
3. oil for lubrication,
4. water–coolant mixture for cooling.