HEUI Advantage Electronic Control Pressurized Fuel to Injection Nozzle
Injection Timing Injection Injection Inje ction Qua Quantity ntity
Intensified Oil Pressure
Pumping Plunger
Injection Pre Injection Pressure ssure Injection Rate Camshaft Ca mshaft Controls 1. How much fuel - how far th e plunger moves.
Camshaft
2. Injection Rate - Rotational speed of cam 3. Injection Injection Timing - When the plunger moves
HEUI System
Conv onve ent ntion iona al Sys yste tem m
ressur zes ue n epen ent y o eng ne spee .
HEUI – Common Rail
HEUI pressurizes fuel speed = Lower emissions, improved power and fuel
Plunger velocities of camshaft actuated fuel
•
engine speeds. •
Poor pressurization and
.
Timing and rate control are fixed in camshaft geometry
•
HEUI Advantage – Superior Atomization
– especially at low speed and high load conditions.
HEUI Advanta es – Hi her Pressurization
g er pressur za on o ue 22,000 – 30,000 psi (2010 G2 injectors). mproves a om za on, mixing and distribution of fuel in the combustion . Promotes shorter ignition delay and burn time. e er o erance or
HEUI - Hydraulically actuated
provides injection force.
Uses ressurized en ine oil as the actuation force for in ectin fuel
ary ng o pressure ena es control of injection rate over all speed and load conditions. Latest injector capable of many different injection shape profiles
Digital Control Valve – Cam-less Diesel High Pressure Oi l
Oil Return
Sturman Digital Control Valve Drive Piston
Use hydraulic system pressure to actuate valves. Variable valve timing. Compression-less starting. Internal braking Improved fuel efficiency and power.
Electrical Suppl y
HE I
m
m
HEUI Injectors Low- ressure oil s stem High-pressure oil system
n n
Typical System Components
-
HI-300A Powerstroke
HI-300B Powerstroke
G2 6.0L Powerstroke
T-444E International
T-444E International
HI450A -3126 Cat
HI450B -3126 Cat
VT 365/275, DT’s International
2nd Generation HI-300 Cat C-7
First & Second Generation
First Generation HEUI Injectors –HEUI A & B
“A”
“B”
HEUI A injector is identified by black coloured solenoid and oes no ave sp -s o capa es . ew e coloured solenoid does (1997 – 2001).
Internal View Solenoid
Poppet Valve Intensif ier Piston
Fuel Inlet
Oil Inlet
Pressure Chamber
Nozzle Valve Fuel Annu lus
HEUI A & B Internal Construction
450 -3,300 psi
Fuel Pressure 30-80 psi
il Injector Tube
F
l
ll ri Cylind er Head
High-Pressure Oil Supply Injector O-Rings Low -Pressur e Fuel Supply
Pass through cylinder head or jumper tube.
Oil & Fuel Galleries Hi h Pressure Oil Pump (Hidden behind reservoir)
Oil Reservoir
High Pressure Oil Rail Fuel Rail Injectors
Plugs on cylinder head indicate the ends of fuel and oil injectors
Oil Flow Schematic
.
High Pressure Oil Pump
Oil Accumulator
Injection Control Pressure Regulator
Accumulator needed for oil supply during servicing and .
Stages of Injection – Major Components Solenoid Poppet Valve Seat
Oil Discharge Port Poppet Valve
Oil Inlet Amplifier Piston Fuel Pressure Chamber
Nozzle
Fill Cycle
Energizing the solenoid lifts the poppet valve and admits oil into the injector.
Injection
Pressurized oil pushes down on the amplifier/intensifier piston. amplifier piston compared to the bottom is approximately 7:1. the piston takes place because of the high ratio
mp
er
ston - top
Amplifier Piston – bottom
Poppet Valve
Poppet valve and amplifier piston
Amplifier Piston op –
c e upon y o
The ratio of the top to the bottom of e amp er ac eves e pressure multiplication required to inject fuel. Amplifier ratio vary between models of injectors typically 7:1 An injector operating with 3,300psi of , injection pressure
Bottom – Acting on fuel
Amplifier Piston
End of In ection Oil vent
De-energizing the solenoid allows the lower poppet valve to return to its seat an open t e upper poppet seat to open. Oil vents out the u on the injector.
er vent ort
The amplifier piston retracts and
Amplifier piston
Pilot - Split Shot Injectors The amplifier piston has connected to holes in the bottom of the injector
roove cross- r e to holes in bottom
Holes drilled in bottom
Pilot – S lit Shot In ection
, degrees before the main injection
-
Pilot – S lit Shot In ection
Pressurized fuel is vented from the annular groove of the amplifier piston as the groove uncovers a spill port next to the plunger barrel. Injection begins then abruptly ends with a small quantity of fuel injected (pilot). The main injection begins after the groove passes the spill port
G2 Injector
Injector Coils
Fuel Inlet
The second generation HEUI injector (G2) was developed for International en ines used also by Ford
G2 Injection Control Valve
Control valve uses two “digital” like solenoids for faster response and improved rate shaping capabilities. (Three injection events in one cycle) Hydraulically balanced, proprietary materials, uses residual magentism to
G2 Injector – High Pressure Oil Supply Oil Manifold
Pressurized en ine oil is su lied b a heav cast iron oil manifold located above the injectors
AWA Fittin s AWA Fittings
Injection Contr ol
Br anch Tube
AWA valves dampen hydraulic pulsations causin in ector “cackle”.
G2 Injector “O” Rings
“ ”
G2 Injector – Fuel Supply
Fuel is supplied to the injectors through a fuel gallery cast into the cylinder head
–
’
High Pressure Oil L ine
Injection Pressure Regulator
.
G2 In ection – Di ital Valve
The G2 injector uses two coils to move a spool valve. The injector also uses an amplifier/intensifier piston which operates similarly to other HEUI injectors The di ital valve overcomes the technolo ical barriers of switchin ver hi hpressure fluid at extreme speeds with reduced coil response time.
Fill Cycle
When the spool valve is closed, oil above the amplifier/intensifier piston is ven e o e a mosp ere.
No current is applied to either
No injection takes place
Main Injection Step 1
A triggering force of 20-amps @ 48volts of current is applied to the coils for only 800 micro seconds. The spool valve rapidly moves a maximum of .017” to admit the amplifier piston.
Main Injection Step 2
Current to the coil stops. Residual magnetism initiates spool valve movement but hydraulic forces continue to open the valve. The amplifier/intensifier piston is forced downwards with oil pressure up to 3,100-psi Injection occurs. An intensifier surface area of ratio of 7.1:1 creates 22,000si in ection ressure.
n o
n ect on
Current pulsed to the spool valve initiates valve closure. Hydraulic forces close the valve Oil above the amplifier piston vents to the atmosphere beneath the valve cover. Injection ends A mechanical relief valve will open at 4,000-psi of oil pressure (maximum theoretical injection pressure of 28,000 psi)
Metering, Timing & Rate Control
All HEUI engines have injection rate controlled by injection pressure. . . .
Metering, Timing & Rate Control
This HEUI injector for Cat C-7 uses a specialized internal valve which provides four different shapes of injection – s uare ram ed ilot in ection and ost combustion injection. Variable pressure is controlled by oil pressure
Metering, Timing & Rate Control
The fast acting digital valve (coils + spool valve) allows for electronic rate shaping of the injection event
Metering, Timing & Rate Control
Pulse width + injection pressure determine the mass or injection quantity. en e n ec on s gna s app e o e so eno s e erm nes n ec on m ng.
High Pressure Oil Systems
A high-pressure oil pump in the valley of the V-8
High Pressure Oil Systems
he 6.0L has the hi h ressure um at the rear of the en ine
High Pressure Oil Systems
High Pressure Oil Systems - ICP
An injection control pressure sensor (ICP) measures oil pressure to
Hi h Pressure Oil S stems -ICPR PWM Electrical Signal
Pressur ze O In
To Oil Sump ECM to electronically regulate oil pressure from the pump. The longer the pulse width, the higher the system pressure. Without a signal all oil flows through the valve to the oil sump
I PR
r i n
To Injectors
Oil From High-Pres sur e Pump PWM Signal From ECM
Drain To Oil
Normally open allowing oil to flow to sump. .
– Injector Drive o ue
ICPR ICP
A closed loop feedback circuit is formed between the ICP and ICPR. and the values reported by the ICP
High Pressure Oil Systems -ICPR
The PWM signal to the ICPR is reported in duty cycle %. s an mpor an p ece o agnos c n orma on o worn pumps and leaking injector “O”-rings
agnose aera e o ,
En ine Control ECM
High voltage, 110-volts DC on earlier HEUI system required the use of a injector drive module to handle the high current flows to the injectors
CAT C7 & C9 HEUI
Hydraulically balanced nozzle vale. Balanced with oil not fuel.
CAT C-7 & C-9 HEUI
Internal ICPR – Variable displacement pump for lower parasitic loss and drive torque.
HEUI Codes
Sensed voltage Hi – Open Sensed volta e Low – Shorted to ground