Contents
4 Are Areas as of use use for for diese diesell engine engines s
4 Suita Suitabi bilit lityy crit criter eria ia 4 Ap Appl plic icat atio ions ns 8 Eng Engine ine ch chara aracte cteris ristic tic data 10 Basic Basic prin princip ciples les of the the diesel engine
10 13 14 17 21 24 25 28 32
Method Meth od of ope opera ratio tion n Torq orque ue and powe powerr output output Engi En gine ne effi effici cien ency cy Oper Op erat atin ing g status statuses es Operat Ope rating ing con condit dition ionss Fuel-in Fue l-injec jection tion sys system tem Combu Com bust stio ion n chamb chamber erss Dies Di esel el fu fuel elss Alte Al tern rnat ative ive fu fuel elss
82 Over Overvie view w of disc discre rete te cylinder systems
82 Single Single-pl -plung unger er fuel-in fuel-injec jection tion pumps PF 84 Unit inje injecto ctorr syst system em (UIS) (UIS) and and unit pump system (UPS) 88 Sys System tem dia diagra gram m of UIS for for cars cars 90 Sys System tem dia diagra gram m of UIS and and UPS for commercial vehicles 92 Over Overview view of comm common-r on-rail ail syste system m
92 93 96 98
Areas of Areas of appli applicat cation, ion, Des Design ign Meth Me thod od of of oper operati ation on System Sys tem dia diagra gram m for for car carss System Sys tem diagr diagram am for for commer commercia ciall vehicles
34 Cyl Cylind inderer-cha charge rge control control system systems s
100 Electr Electronic onic diese diesell control control EDC
34 35 38 38 49
100 Requirements, Requirements, System overview 101 Sys System tem struct structure ure 102 Applic Application-r ation-related elated adaptat adaptation ion of car engines 106 Applic Application-r ation-related elated adaptat adaptation ion of commercial-vehicle engines 111 Cali Calibra bration tion tool toolss
Overv rviiew Intak In takee-air air fi filt lter erss Swir Sw irll fla flaps ps Turboc urbocharge hargers rs and super superchar chargers gers Exhaus Exh aust-g t-gas as reci recircu rculati lation on
50 Basic Basic prin princip ciples les of of diese diesell fuel-injection
50 52 54 55 60 61
Mixture Mixtu re distr distrib ibut ution ion Startt of inje Star injecti ction on and and delive delivery ry Inject Inj ecteded-fue fuell qua quantit ntityy Inject Inj ection ion ch chara aracte cteris ristic ticss Inje In ject ctio ion n pres pressu sure re Inject Inj ection ion direc directio tion n and number number of injection jets
62 Overvi Overview ew of diesel diesel fuelfuel-inj inject ection ion systems
62 Requ Requir irem emen ents ts 64 Design igns
114 OpenOpen- and and closed closed-lo -loop op electronic control
114 Open- and closedclosed-loop loop contr control ol 114 Data pro proces cessin sing g 116 Ac Actu tuat ator ors s
116 Electropneum Electropneumatic atic conver converters ters 117 Continu Continuous-ope ous-operation ration brakin braking g systems 117 Fan cont control rol func function tion 118 Star Start-a t-assis ssistt systems systems 120 No Nozz zzle les s
70 Overview Overview of in-lin in-line e fuelfuel-injec injection tion pump systems
122 Future develo development pment of the nozzle
70 Areas Areas of of applic applicatio ation, n, Type Typess 71 De Desig sign, n, Con Contr trol ol
124 Noz Nozzle zle hol holder ders s 126 Exhaus Exhaust-gas t-gas treatm treatment ent system systems s
74 Overvi Overview ew of dis distrib tributor utor fuel-injection pump systems
74 Are Areas as of applic applicatio ation, n, Design Designss 76 Por Port-c t-cont ontroll rolled ed sys system temss 78 Sol Soleno enoidid-valv valve-c e-cont ontrol rolled led sys system temss
126 Diesel oxidatio oxidation-type n-type catalyti catalytic c converter 126 Par Partic ticulat ulate e filter filter 127 NOX accumulator-type catalytic converter 129 SCR pri princ ncip iple le 129 Comb Combinat ination ion syst systems ems 130 Ind Index ex of techn technical ical term terms s
131 Abb Abbrev reviat iations ions
The diesel engine is enjoying a period of increased popularity among motorists. Its traditional strengths are economy, reliability and high-torque output. That is why it became established as the engine of choice for commercial vehicles a long time ago. The continuing development of the diesel engine – and particularly of the direct-injection design – coupled with the rapid advances made in high-pressure fuel-injection systems have consistently brought about further improvements in performance and consumption. Furthermore, modern diesel engines with high-pressure fuel injection have made substantial progress in respect of driving smoothn ess and pollutant emission. They need no longer fear comparison with any other type of internal-combustion engine. This has led to the diesel engine becoming a much more popular choice for cars – including sports cars and luxury-performance cars. With the increasingly widespread use of the diesel engine, the desire to understand more about it has also grown. This manu al in the “Automotive Technology” series offers an up-to-date insight into the workings of the diesel engine. It also describes the various Bosch fuel-injection systems. Consequently, it provides a comprehensive view of components in dieselengine management systems. This series of publications also includes other titles that examine in more detail the diesel fuel-injection systems and the electronic diesel-control system EDC outlined in this manual.
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Overview of common-rail system
System diagram for commercial vehicles
System diagram for commercial vehicles Figure 4 shows all the components of a fully equipped common-rail system for a six-cylinder diesel commercial-vehicle engine. Depending on the type of vehicle and application, some of the components may not be used. For the sake of clarity of the diagram, only the sensors and desired-value generators whose true position is necessary to the understanding of the system are shown in their fitted locations. Fig. 4 Engine, engine control unit and high-pressure injection components
22 29 30 31 32 33 34
High-pressure pump Electronic engine control unit Fuel rail Fuel-rail pressure sensor Fuel injector Relay Auxiliary equipment (e.g. retarder, exhaust flap for engine brake, starter motor, fan) 35 Diesel engine (DI) 36 Flame glow plug (alternatively grid heater) M Torque A
Sensors and desired-value generators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Accelerator-pedal sensor Clutch switch Brake switches (2) Engine brake switch Parking brake switch Control switch (e.g. cruise control, intermediate speed control, engine speed and torque reduction) Starter switch (“ignition switch”) Charge-air speed sensor Crankshaft speed sensor (inductive) Camshaft speed sensor Fuel temperature sensor Engine-temperature sensor (in coolant system) Charge-air temperature sensor Charge-air pressure sensor Fan speed sensor Air-filter differential-pressure sensor
B
Int erfaces
17 18 19 20
Air-conditioning compressor with control Alternator Diagnosis interface SCR control unit
Data exchange with a wide range of other systems (e.g. transmission cont rol system, traction control system TCS, electronic stability program ESP, oil quality sensor, tachograph, radar sensor ACC, vehicle management system, brake co-ordinator, fleet m anagement system ) involving up to 30 control units is possible via the CAN bus in the “Interfaces” section (B). Even the alternator (18) and the air-conditioning system (17) can be connected to the CAN bus. For exhaust-gas treatment, three alternative combination systems are shown (a, b and c). 21 Air compressor CAN Controller Area Network (vehicle’s serial data bus) (up to three data busses) C
Fuel supply system (low-pressure system)
23 24 25 26 27 28
Fuel pump Fuel filter with water-level and pressure sensors Control unit cooler Fuel tank with filter Pressure limiting valve Fuel level sensor
D
Air intake system
37 Exhaust-gas recirculation cooler 38 Control flap 39 Exhaust-gas recirculation actuator with exhaust recirculation valve and position sensor 40 Intercooler with bypass for cold starting 41 Turbocharger (in this case with variable turbine geometry) with position sensor 42 Charge-air pressure actuator E
Exhaust-gas treatment systems
43 44 45 46 47 48 49 50 51 52 53 54 55 56 57
Exhaust-gas temperature sensor Oxidation-type catalytic converter Differential-pressure sensor Particulate filter Soot sensor Fluid level sensor Reducing agent tank Reducing agent pump Reducing agent injector NOX sensor SCR catalytic converter NH3 sensor Blocking catalytic converter Catalyzed soot filter Type CSF Hydrolyzing catalytic converter
Overview of common-rail system
4
System diagram for commercial vehicles
Common-rail diesel fuel-injection system for commercial vehicles
B
23
CAN 17
C
24
27
22
25 26
28 18
G
19
20
31
30
29
21
32
A
33
1
34
2 37
3
36 35 38 39
4 D
M
5 40
6 7
41 42
8 43
9
43
45 46
44
a
E
47
10 48
50
11 49
51
12 13 14
48
c
54 55
50 45 43
51 52
43 16
53
49
15
43
52
44
b
52 or 54
56
57
53
44
54
Y 0 2 8 1 K M N
æ
99
