2011 Automobile Maintenance
Advanced Course for the
Industrial Technical
Instructors
No.:
----------
Name:
AcP\
\-'\~ 1:.
Instructor:
\~~
Lin
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Emissions legislation
• Emissions legislation for Diesel passenger cars
State-of-the~art
technology
2004
%
USA
Japan
EPA CARS
.__ ~.Q~t4__
100
.~.9P~...__
BinS ULEV
50
0014
o
--t-- - - - - - - -
100 - - -___
50
o .._ij!~~~~~~~~~~~~~~~~~-~~&L~-~O~1~7~ 100 -~~
21.~
2 ~·----------------
EGER
50-
15/04
CO
0 -······ ··· ·
1990
Source: Bosch
Figures
1
=emissions limits in glkm
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Conclusions
1. Comparison with traditional pumptype diesel injection system
2. Development trend of common rail
injection technology
3. Problems generated following the
development of common rail fuel
injection technology
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Thank you
~~!
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PM filter CDPF)
=Particulate matter/Partikel
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Active DPF regeneration
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Piezo inline injector
Source: Bosch
Post-processing System of
Exhaust Emissions
Engine control :co:m:p:u~
te~rJ~~~~~~~~~~~:S~;=!!!!===ll· ·='l"""'"--""'----"'"l
Temperature
sensor
Air-fuel ratio sensor
Temperature
Air-fuel ratio sensor
To collect the final PM residues
Suck up NOx temporary, and through the control and management
of engine to reduce it into N2 under the absence of 02
Use oxidation to remove CO, HC and a portion of catalyst with PM constitution.
Convert them into harmless C02, H20 and other substances, and convert NO into N02.
Source: Bosch
o
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How to Pass EURO 4 Certification
• 1. Use low-sulfur diesel
• 2. Adopt post-processing system
(recommend to use low-ash engine oil: E4
grade)
rv
E6
• DOC
. SCR
• DPF (CR-DPF)
• High volume of EGR
• 3. Use 3rd generation common rail system with
piezoelectric injection nozzle
• Capable of passing EURO 4 certification without
using DPF
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3RD generation CRS
19
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Post-injection
- - - - - - - - - -- - - -,==,="='''''=
• What is the post-injection:
• A small certain amount of fuel injection
after main injection
• Advantages:
• Reduction in NOx-emisissions
• Disadvantage
• Slightly increased fuel consumption
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Fuel efficiency comparison with
conventional models
(km/L)
15~--------------~
14
14.0
f---
--------------1
Old model
If ill
New model
11 .2
11
10.2
10
9
8
7
6
5
Caldina
(2.0L)
Test mode: 10-15 mode
Alphard
(3.0L)
18
Land Cruiser
Prado
(Diesel)
Hilux Surf
(Diesel)
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Consequences of pilot-injection
• Pre-conditioning of the combustion space for
the main injection process both in terms of
pressure and temperature.
• Ignition delay for main injection is shortened
• Noise advantages (reduced peak combustion
pressure)
• Optimum combustion
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Injection Activation possibility
• Pilot injection):
0
From 90 before Toe to 100 after TOe
• Main-injection:
0
From 20 before Toe to 100 after TOe
• Post-injection:
0
From TOe to 200 after TOe
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Split Injection
• Timing : low temperature starting
Split
injection
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Aim of pilot-injection
• Reduction in :
• Combustion noise
• HC Emissions
• Fuel consumption (late injection start)
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The Effect of Pilot Injection on Injection
Rate and Heat Generation Rate
Injection rate control
Conventional
Injection rate
Big pre-mixed
combustion
(NOx, noise)
Heat
generation
rate
-20
TOC
20
40
Crack angle (deg)
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Pilot Injection
Before
25°
20°
15°
TDC
10°
5°
After
0°
-50
'/
b1)
....ro
~
-- Jf
1-
I
Voltage waveform
f---
I--'-
.-r-:
.- ~
. ~
1 .•.. ..
1 = Pre-injection
L
/ V.""
IJ/
,.,
,~
.
2-
-15°
I~
'\
:~ ,
r
A. ...
..
~,
"""
-20°-25°
~
~T :f"
(!)
_10 0
1... ......... :.
h..
" ""
i\
. .L •
~
la = Combustion pressure with pre-injection
2 = Main injection 2a = Combustion pressure without pre-injection
15
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Ideal Injection Timing and Injection Volume
(Rate)
Main
Pilot
After
Main
injection
Pilot injection
The fuel injection in
hope of generating an
easy combustible
mixed air in the
combustion chamber
beforehand.
t
Reduced PM
Post
After injection
Post-injection
The fuel injection in
hope of generating a
seed fire in the
combustion chamber.
A supplemental fuel
injection in hope of
enhancing complete
combustion of residue
fuel.
Retced NOx
Reduced noise
Reduced PM
There is no such
injection in original fuel
injection control system.
It is the fuel injection in
hope of enhancing postprocessing effect of
exhaust emissions.
Pre-injection
t
ReducJd NOx
Source: Bosch
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Pilot Injection
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Magnetic injector
Source: Bosch
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Basic Injection Rate Control
• Main injection
• Pilot injection or Pre-injection
• Small amount of fuel injection before main
injection
• Spl it injection
• Small amount of fuel injection before main
injection while starting
• Small amount of fuel injection, no need preheating
• Post-injection
• Small amount of fuel injection after main injection
13
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System Composition of CRS
----------------1
[c----:-:~~P?~ ltl?~~~~~?~ r-· Engine control
I
Crank position sensor
!
computer
,...........................................................-.-.... - - i
~--..
'
[~y?~~-.~?_~~nsors J--_ I~: : : : : : : : : : : : : : : : : : : : : : : : : : ~
---+
Rail
pressure
---+
Common rail
t
I
I
,
sensor
-
i
I
Orifice
/
Intake regulation
valve (MPROP)
'-------'
High pressure area
Low pressure area
Fuel tank
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Fuel System
Injection
Pressure
PCV
control
signal
control
~
Supply Pump
Common Rail
-
Injector
-------1J----------------~~~~~-----------jJ;~yPre-
Filter
p
Fuel Tank
12
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Classification (cant.)
•
Classified by common rail installation position
Located in engine cylinder
head (bottom fuel intake)
• VW TDI - UIS
• HEUI
Located outside of engine
cylinder head (top fuel intake)
• BOSCH CRS
• DELPHI CRS
• DENSO CRS
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Main Features of Electronic Control
Type CRS
Cilluto
•
•
•
•
•
Uses high-pressure injection throughout the operation range
• Lower exhaust emissions
• More consistent engine power performance
Injection rate (volume) control
• Reduced exhaust volume
• Reduced engine noise
Injection timing can be set flexibly
• Improved performance
Control injection pressure solely according to engine revolution
and load changes
• Injection pressure will no longer increase following an
increase in engine revolution
• Able to maintain high pressure even in low speed
Improved starting performance, reduced white exhaust smoke
11
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VW TDI - UIS
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Classification
•
Classified by common rail fuel pressure
Low-pressure common rail
• VW TDI - UIS
• BOSCH CRS
• DELPHI CRS
• DENSO CRS
• HEUI
•
High-pressure common rail
Classified by fuel injection control method
Mechanical + Electronic
Control
Electronic Control
• BOSCH CRS
• DELPHI CRS
• DENSO CRS
• VW TDI - UIS
• HEUI
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Denso ECD U2 system
9l11tO
Car System Diagram
IJ_'
_ _ _ __ _ _ _~_~~~=2 ...
'C
Flow regulator
r 1·.; ->I~ject:ns:~n:::~~;fdiV=d x, ':tP- - - - - - - - - -:- - - - - - - - - - - - - - - - - -- - --I
.
I
I
I
I
I
I
I
I
I
I
. _'M'~.;~
!!l.l!~"~'/".;;;; ~~,;,,;:~, ~.:~.:;;: :-'y;.lt.'M*(Ijj~S:lJ!.
• Injection volume control
I
I
Injector
I
I
• Injection pressure control
~;
-
~.!;,-t. -:'i1 :J
"t \ Ll :;q.l~
r.
~ . Il,:'·alatl f~Hp};f!1iJ
:; _ r Engine, Car !Hl
~
'.:
NE sensor
(Crank position sensor)
.. . .
~
~.~
~
:- ,
NE !t~jlllffi
I
I
d.....
~m.ljdl\Jfifi<.ii
Injection timing control
•
I
I
I
Common rail pressure sensor ddd' d... · . .. ..... ... ...
(,tMill (I:jJl:t!\B Accelerator pedal sensor
." _ Arr ECU :i!!!' communication
,- ABS/ASR ECU iilH;;
- INOMAT ECU litH,:;'
I
Pressure sensor
Water 'temperature sensor
." ---ir---flIt= '1 Fuel temperature sensor
~---f---d1t:l1 .< Car speed sensor
~illit.K&JJ[!~~:rlH:~
j
Supply pump
G sensor
(Cylinder differential sensor)
G F5);nH:~
(~tu:.~}1jjjU }.;.1i(fn;'}fi )
..1()iliMi?Tl<'~
Fuel injection rate co
;W.k~[4ni't.H, hk< blithl
IL Communication
_ _-...,.--....
} ;'
I
.. '~'~. ' .-' ~: Fuel injection volume
" I
..•
r
I
~!!'iIj.'='di*... ,~.~=:....~~:p. .;.;.;.; ;. ;. ;...
.; ; .~,.,=~.~
I
-......... _:'d ', ' Fuel injection timing
fJ(~1~~j.I!tj}.}J 1~ \J'JVj1:'tOljJ~ i ·
d. dd "dd d 'd ... ..............._.........'. _...." -, I
.1.
I
I
I
~~~~/-I~C:
I
Fuel injection pressure
CPAV (common rail pressure
- ,::::.:~~--.::.,,:.::.,·:.::...·:..... · . .: .:· : .:.:,·.....:~~i
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Caterpillar HEUI fuel system
.3. High Pressure Oil Pump
4.lniector Actuation
Pressure ConlrDI Valve
1. Inlectots
Four basic components work together to bring precision, reliability and simplified
maintenance to the HEUI fuel system.
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The Main CRS Types
• Bosch
• Denso
• Market mainstream
• BMW, RENAULT, BENZ,
VW, VOLVO, Hyundai,
KIA ...
• Japanese
mainstream
• Code: ECD-U2
• Mitsubishi FUSO
• Isuzu (6H Kl-TC)
• Hino(K13-C)
• Delphi
• Other makers
• GM
• Caterpillar
• Hyundai,
KIA,
• Code: HEUI
Ssangyong
• ISUZU ( 4JX1-TC)
• Siemens
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Bosch CRS for passenger cars '
•
Bosch Common Rail System for passenger cars
(j) Air mass meter
® EngineECU
@ High pressure pump
@ Common rail
E~;C·::.:~.c:,O' ..
(g) Injectors
@ Engine speed
sensor
(J) Coolant temp.
sensor
@ Filter
@ Accelerator
pedal sensor
Source: Bosch
8
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What is a Common Rail system
• Diesel accumulator fuel-injection
system
• A accumulator named Common
Rail is a fuel distribution pipe
• Electronic engine management for
direct injection diesel engines
• Electronic diesel control (EDC)
• Start-assist system
• Emission control
• DI
+ Turbo
= TDI
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Common Rail System Addressed by Different
Car Makers
• FORD : TDCi (Turbo Diesel Common-rail
direct Injection)
• Benz: CDi (Common-rail direct Injection)
• BMW: 320"D", 530"D" (An added D at the
rear of car model)
• Bosch: CRS
• Land Rover: TdV5 , TdV8
• VWj Audij Skodaj Seat: TDi
• Hyundaij KIA: CRDi
• SSangyyong: XDi
• Renault:
7
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High-Pressure Injection System (01) - Passenger Car
Market
High-pressure injection systems from Bosch :
Installation in passenger-car diesel engines
DCRS
. VP44
100% - 80%
---l
60%
---l
80
66.1
40%
--l
20% - 21,2
0% ,---2002
2006
Source: Bosch
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High-Pressure Injection System (01) - Total Market
The market for Bosch diesel injection systems:
breakdown by product groups
100%
9.5 Mio.
systems
Plan: 11 Mio.
systems
,,"> '''''~-'"-~-"
,- - -- "' -
UIS/UPS
80%
60%
40%
Inline- and distributor pumps
20%
0%
2002
2006
6
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Unit Injector system CUIS)
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Bosch Common Rail System
5
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Bosch VP44 Radial-piston Distributor Pump
CD Radial-piston distributor
pump with integrated
engine/pump control
unit
® Glow control unit
@ Injection nozzles
@AirMmass meter
@ Pedal-travel sensor
CP) Crankshaft speed sensor
(J) Sheathed-element glow plugs
(,6) Engine-temperature sensor
® Fuel filter
Source: Bosch
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VP44 Radial-piston Distributor Pump
4
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Countermeasure 2
• The higher the injection pressure, the
higher the thermodynamic efficiency.
• The higher the injection pressure, the
injection duration will be shorten.
• This makes the direct injection (01)
diesel engine become the most
thermodynamically efficient of all the
internal combustion alternatives.
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Diesel DI systems by Bosch
VP44
eRS
UIS
UPS
Radial-Piston
Distributor
Pump
Common-Rail-
Unit-I njectorSystem
Unit-PumpSystem
System
Accumulator/Rail
High pressure
Pump
Source: Bosch
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Clean diesel Emission
, - - -. Common roil M1
injectfon system
I
;
t
f
i
! expanded
I' vliew
(DPNR: Diesel Particulate and NOx Reduction System)
Source: Toyota
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Countermeasure 1
• Diesel management system