www.siemensvdo.com

Dynamic and fuel efficientInnovative solutions for gasoline engines

Mobility shapes our life –moving ahead is our passion

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Our passion for mobility helps us attain newgoals. Mobility is freedom – and for us, as aworldwide supplier to the automotive in-dustry, it is both our vision and our fascina-tion. Our enthusiasm for technology in allsegments of modern automotive electron-ics and mechatronics unites Siemens VDOemployees across geographic and linguisticboundaries.

An open mind for what’s new is just as impor-tant to us as experience, focused researchand development. That’s why specialistsfrom the most diverse business sectors worktogether within our company. Our innovativedevelopments are proof of the success of thisoperational model.

Despite the existence of a range of alterna-tives, most vehicles continue to be fittedwith gasoline engines. Excellent drivingdynamics – and particularly the extendedengine speed range – are a key purchasingargument for many consumers. At the sametime, politicians and society are calling forsignificant reductions in fuel consumptionand emissions.

We help make vehicles more reliable, morepowerful, and cleaner by creating innovat-ive product and system solutions for gaso-line engines with port and direct injection.

As leaders in innovation, we have set newstandards with many of these develop-ments. We were the first supplier to developa marketable piezo injection system for die-sel engines, offering major benefits interms of precision and efficiency. Thisgroundbreaking technology is now beingapplied to gasoline engines, and we areonce again up with the frontrunners.

But we offer vehicle manufacturers morethan just injection systems and the associat-ed engine management electronics. As aproven and efficient partner, we offer sup-port throughout the entire development cy-cle of a new engine or vehicle – from jointspecification of the system architecturethrough simulation, testing, and calibrationto the start of series production and associ-ated support. Our experts and state-of-the-art test centers are available to every manu-facturer, worldwide – in the United States,Asia, and Europe.

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Modern engines that provide drivingfun and a clean conscience 4

Systematic optimization 6

EMS 2 – a platform for success 8

Piezo direct injection –direct and efficient 10

Increased torque at low engine speeds –solenoid direct injection 12

Additional innovative componentsfor direct injection systems 14

Tried and true – port injection 16

Flexible savings – with alternative fuels 18

More than ever before, many contradictoryrequirements need to be reconciled whendeveloping internal combustion engines.On the one hand, politicians and societydemand reduced fuel consumption, emis-sions, and costs. On the other hand, power,torque, and responsiveness are becomingincreasingly important purchasing criteriafor many consumers.

Reducing emissions and fuel consumption

Strict emission limits, particularly for newvehicles, apply in most industrialized coun-tries and in many emerging countries aswell. The authorities are exercising a pow-erful influence on levels of carbon monox-ide (CO), nitrogen oxides (NOx), and hydro-carbons (HC) in exhaust gases by means ofstringent approval criteria for manufactur-ers, fiscal penalties, or direct subsidies.

The United States, and particularly Califor-nia, are at the forefront of these trends, im-posing extremely stringent limits for CO,NOx, and HC emissions. A vehicle that ful-fills the current requirements only emits afraction of the pollutants regarded as stateof the art 25 years ago.

This is an ongoing process. In Europe, politi-cians and manufacturers are already debat-ing details of the upcoming Euro 5 stand-ard, while in North America, a firm

Modern engines that provide drivingfun and a clean conscience

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Main market drivers for combustion engines

Leg

isla

tio

nM

arke

t

Emission Fuel Economy

Performance / Torque Cost benefit ratio

CO

CO2 [g/km

]

NOxHC

Fun to

driv

e

Cost b

enefit ra

tio

Emission regulations US-Federal / US-California

3.5

CO [g/mi]

0 1.0 2.0 3.00.10.20.30.4

NOx [g/mi]

HC [g/mi]

0

0.25

0.05

0.10

0.15

0.20

TIER 1

TLEV

LEV 1

ULEV 1

LEV 2

ULEV 2SULEV

1995 2015100

110

120

130

140

150

160

170

180

190

200 ACEAcommitment-25%

EUproposal-14%

CO2 [g/km]

Year

2000 2005 2010

ACEAreal data

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timetable for a further reduction of emis-sions is in place.

In Europe, in addition to pollutant reduct-ion, attention is being focused on achiev-ing a significant decrease in consumption toreduce the emission of the greenhouse gascarbon dioxide (CO2). The members of theEuropean Automobile Manufacturers' Asso-ciation (ACEA) have already committedthemselves to cutting average emissions ofCO2 to 140 g/km by 2008. This correspondsto a reduction of 25% since 1995.

At the same time, a further tightening ofthe CO2 limit is already under discussion inthe EU. The aim is to cut overall consumpt-ion by another 14% by 2012, meaning thatan average of only 120 g of CO2 is emittedper kilometer.

With rising fuel prices and correspondingrecommendations from the California AirResources Board (CARB), cutting carbon di-oxide emissions has also become a subjectof increasing importance in the UnitedStates. Similar CO2 limits to those in Europewill apply following full introduction of theGreenhouse Gas Regulation in California in2013.

Huge progress has already been made interms of emissions and fuel consumption inrecent years, particularly by using electronic

control units. Future development will fo-cus on a range of aspects – the major chal-lenge with regard to diesel engines is reduc-ing emissions, while lowering fuelconsumption is the priority for gasoline en-gines. Major efforts are required to meetthe tough CO2 targets.

The fun factor remains important

The sheer pleasure of driving, expressed interms of performance, torque, and respon-siveness, remains key for consumers whenthey come to make their purchase decision,alongside vehicle price and operating costs.This makes the challenge of developing in-novative engines, engine management elec-tronics, and injection systems that complywith the new emission and consumptionregulations all the greater. The attraction ofperformance is reflected in the statistics forfirst-time car registration in Europe: in 1993,the average power output according to ACEAfigures was 63 kW, while ten years later thefigure was 79 kW and still rising.

Innovative solutions are needed

Our response is a commitment to providingadvanced injection and engine manage-ment systems that allow these apparentlycontradictory demands to be reconciled,

thus demonstrating that respect for the en-vironment and driving enjoyment are com-patible objectives.

CO2 reduction roadmap for the EU

Torque Gasoline MPITurbo charged

Diesel DITurbo charged

1000 70003000 5000

Driven by current market trends, develop-ers working to optimize gasoline enginesfrequently pursue two objectives, i.e. tocut fuel consumption and simultaneouslyboost performance. The emphasis is onreducing both frictional losses and throt-tling losses in part-load operation.

The methods used to achieve these objec-tives are mainly dependent on engine sizeand the type of vehicle. Having said that,the range of individual technologies nowavailable to automotive manufacturers ishuge. These approaches may be com-bined or used individually to produce thedesired result. The most important arevariable valve trains, turbocharging, andgasoline direct injection.

The result of implementing all these tech-nologies is a more complex engine, withexisting electronic control units alreadyholding up to 4,000 operating maps anddata points. Extrapolating from today’ssituation, future engine managementsystems will need to provide a stable, reli-able platform based on a modular archi-tecture that can easily accommodate newrequirements. This is vital with regard toboth engineering and commercial consid-erations.

Full of potential –gasoline direct injection

Gasoline direct injection offers the greatestpotential for enhancing performance andminimizing consumption. Compared withconventional port injection, it extracts morepower from a given size of engine, deliversbetter dynamics, and enables emission lev-els and consumption to be reduced. We arepursuing a dual strategy that reflects theneeds of different markets and models: sole-noid direct injection, and piezo direct injec-tion via ultra-fast, highly accurate piezo in-jectors. The piezo technology in particularhighlights our leading contribution to thedevelopment of injection systems. We werethe first supplier to put this technology intoseries production for diesel engines, and arenow – again as one of the first – transferringit to gasoline engines.

With large-capacity engines and in marketswhere low-sulfur fuel is available, we see acombination of spray-guided combustion,piezo injectors, and NOx storage catalysts asoffering the greatest potential for cutting fuelconsumption.

For turbocharged gasoline engines with vari-able valve timing and homogeneous com-

bustion, our solenoid direct injection sys-tems offer considerable potential comparedwith port injection for saving fuel, reducingemissions, and increasing torque at low en-gine speeds.

Still relevant – port injection

Despite the exciting prospects offered by di-rect injection systems, port injection (or multi-point injection – MPI) will remain the domi-nant system in the immediate future, particu-larly for small, low-cost engines. Far from be-ing outdated, engines using this technologyincreasingly feature variable intake systems,cam phasing and high exhaust gas return ratesto save fuel, increase power and torque, andoptimize the combustion process.

Systematic optimization

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DT

CO2 reduction potential in comparison to aregular MPI gasoline engine Torque characteristics of high boost turbo charged engines

Potential of CO2 reduction

MPI Naturally aspiratedDual VVT

Continuous VVL inlet

DI homogeneousTurbo Charged

Dual VVT

0% 10% 20%

MPI Naturally aspiratedDual VVT

DI stratifiedNaturally aspirated

Dual VVT

min. max.

Gasoline DITurbo charged

Engine Speed in rpm

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Open for alternatives

The steady increase in gasoline and dieselprices is helping to generate interest in alter-native fuels, such as natural gas (CNG), liquidpetroleum gas (LPG), ethanol, and – lookingfurther into the future – hydrogen (H2).

We have studied this market in depth andidentified an approach that allows economi-cally viable flexibility with regard to futureengine concepts. For example, for CNG/LPGapplications we offer automotive manufact-urers the choice between a fully integratedengine management system and an auxilia-ry control unit for the CNG/LPG-specificfunctionalities which allows retention ofthe standard MPI ECU. This strategy makesour systems a flexible solution for many en-gines from different manufacturers.

Joining forces – hybrid propulsion

We are observing an increasing demand forhybrid vehicles, which are an important ele-ment of our mobility concept for the future.Using an electric machine to supplement a

gasoline or diesel engine can make it easierfor conventional engines to fulfill future fu-el consumption and emission requirements,while simultaneously satisfying the vehi-cle’s increasing electrical power demand.Moreover, these concepts enable new vehi-cle functions and can also boost drivingpleasure by making use of the attractivetorque characteristic of electric machines.

We have many years of experience in thedevelopment and manufacture of electricalmachines and power electronics. Workingclosely with our partners, we are thus in aposition to deliver attractive system solut-ions for the growing hybrid market.

A proven partner – Engineering Servicesfor engine management systems

Our ability to develop and manufacture thenecessary components is backed by a flexi-ble service concept designed to meet thespecific needs of automotive manufacturers– our Engineering Services for engine man-agement systems. This global team of over500 experts provides comprehensive know-

how, intelligent tools, processes, and simu-lations to support the development, calibrat-ion, and system integration of both gasolineand diesel engines.

Whether port or direct injection, three cylin-ders or twelve, automatic transmission ormanual, Euro 4 or LEVII, sports car or mini-van, our offerings cover everything fromcalibration support to complete turnkeyprojects.

We team with our customers from the firststages of the design process right throughto the joint development of system architect-ure, simulation, and calibration to testingon one of many test benches, and support-ing the start of series production. Thismakes us the perfect partner when it comesto taking performance from the lab to theroad.

New engine functions such as gasoline di-rect injection, and ever stricter consumpt-ion and emission targets, introduce awhole new level of engine managementcomplexity.

Innovative engine management systemstherefore need to be modular in order tomeet demanding quality objectives despiteshorter development cycles and an evergrowing number of variants.We have developed a modular and scalable32-bit engine management platform –EMS 2 – that sets a new industry benchmark.

Smart architecture

Our EMS 2 platform builds on a generic sys-tem architecture at function level that allowsmodel-based mapping of the physical reality.The individual modules that make up this sys-

tem architecture – the so-called “aggregates“ –are complete functions that are largely inde-pendent of each other and feature preciselydefined interfaces and tasks. All these aggre-gates can be combined and adapted in indi-vidual development projects and are alsolargely independent of the underlying hard-ware. The key benefit here is the ability to usethem with different processor types. Manu-facturer-specific function modules can also beintegrated quickly and flexibly thanks to thisopen platform architecture.

EMS 2 –a platform for success

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Gasoline EnginesDirect Injection

Gasoline EnginesPort Injection

Diesel EnginesDirect Injection

Common Function Platform

Common Hardware Platform

Common Components Platform

EMS 2 platform

Transfer

Aggregate 1Version A

Aggregate 2Version A

Aggregate 3Version A

System 1

Aggregate 2Version B

Aggregate 3Version B

System 2

Exchange

Aggregate 1Version A

Aggregate 1Version B

Aggregate 2Version A

Aggregate 3Version A

System 1

ImportSystem 1

Aggregate 2Version A

Aggregate 3Version A

System 1

Aggregate xCustomer

Engine Control Unit EMS 2

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Technical data EMS 2:

Max. CPU clock: 40 to 150 MHz

Flash controller internal: 1 MB to 2 MB

Flash external (optional): Single chip/2 MB

RAM: 32 kB to 144 kB

SPRAM: 8 kB to 48 kB

CAN bus interfaces: 2 to 4

FlexRay interface: optional

Digital inputs: 10 to 52

Analog inputs: 16 to 36

(4 fast ADC)

H-Bridges outputs: 1 to 4

Low-side/High-side drivers: 16 to 36

Ignition outputs: 3 to 8

Standardized yet flexible

EMS 2 can be used with all types of gasolineengines, diesel engines, and bi-fuel and hy-brid systems. The functions are also de-signed in such a way that EMS 2 can meet allcurrent worldwide demands with regard toemission limits, while additionally support-ing extensions for more restrictive future re-quirements.

In addition to being modular, scalable, andflexible in terms of software, EMS 2 offers achoice of various processor types, housings,and connectors. This makes EMS 2 a trulyuniversal solution.

With EMS 2, we offer vehicle manufacturersan engine management system that can becustomized to meet their individual require-ments while ensuring maximum qualitythrough the use of proven standard mod-ules.

By using Piezo direct injection we facilitatestable lean combustion in stratified operat-ion, thereby achieving the greatest possi-ble fuel savings throughout an extendedengine operating range. Compared with aconventional gasoline engine with port in-jection, this technology can reduce fuelconsumption by up to 20%, depending onthe type of vehicle and driving cycle.

Hence our experts favor a spray-guidedcombustion process, which has significantthermodynamic benefits over wall or airguided combustion. The result is near-optimal combustion.

This injection technology leverages the spe-cial properties of piezo ceramics, whichchange shape in a fraction of a millisecondwhen electric current is applied. This allowsfar more accurate control of injectors thanmagneto-inductive or mechanical princi-

pals. In conjunction with an outward-opening nozzle – which is less susceptibleto deposit build – this combination of injec-tor switching speed and metering precisioncreates ideal conditions for spray-guidedcombustion.

In stratified operation, the fuel is injected athigh pressure toward the spark plug at theend of the compression stroke. This extreme-ly short time slot provides the optimum con-ditions for creating the best possible air-fuelmixture, but precision timing is crucial.

Piezo direct injection –direct and efficient

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Technical data piezo injector:

Working flow range: > 50

Static flow: > 35 g/s

Minimum dynamic flow: < 2 mg/stroke

SMD size: ~15 µm

Injections per cycle: up to 4

Opening/closing time: ≥ 150 µs

System pressure: 5 to 20 MPa

Mounting position: Central position

Spray angle: 90°

Piezo injector

High pressure for maximum efficiency

For cleaner combustion, it is important to en-sure extremely fine atomization of the fuel.High operating pressure and smart nozzlegeometry are essential if a piezo injector is todeliver the best results. The injector is de-signed for a pressure of 20 MPa, at which itachieves a surface mean diameter (SMD) of15 µm, thus creating optimum conditions forspray-guided combustion.

During stratified operation, typically smallervolumes of fuel are injected, calling for ex-tremely short injector opening times of only0.1 to 0.6 ms. Theoretically, inaccuracycould be a problem, but measurements on

our new piezo direct injection system showoutstanding repeatability of the injectionvolume, even with such short cycles.

In particular, piezo injectors allow precisely-timed, precisely-metered multiple injectionsin the light and medium load range to ensurestable combustion with low cyclical fluctua-tions. In stratified operation, the quality ofthe fuel feed is also enhanced by the piezo el-ement's ability to not only completely but al-so partially open and close the injector.

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Piezo injector: nozzle and spray pattern

Increased torque at low engine speeds –solenoid direct injection

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Solenoid direct injection is the more cost-effective form of gasoline direct injectionfor engines with homogeneous combust-ion. When combined with variable valvetiming and turbocharging, this technologyalso offers exciting opportunities to realizehigh performance gasoline engines with re-duced fuel consumption, making smartdownsizing possible.

Contemporary gasoline engines with port in-jection and turbocharging frequently sufferfrom a delayed response at lower enginespeeds, known as “turbo lag.” Because theturbocharger does not react immediatelywhen the driver presses the gas pedal, onlylimited torque is available during initial accel-eration. The torque issues implicit in down-sized turbocharged engines can be partially

overcome by deploying direct injection to-gether with variable valve timing. Increasingthe valve-opening overlap at low enginespeeds by means of a cam phaser leads to a“scavenging” effect, whereby the pressuregradient between the intake and exhaustsystems draws air through the cylinder. Withdirect injection technology, the injection tim-ing can be set to avoid fuel being sucked intothe exhaust system prior to combustion, ashappens with port injection. Scavengingboosts torque at low engine speeds by vir-tue of a number of specific engine effects.The benefits include much reduced turbolag and torque characteristics more closelyresembling those of a diesel.

The fuel vaporization associated with directinjection also reduces combustion chamber

temperatures, thereby reducing the tendencyof knocking. This allows higher compressionratios and therefore lower fuel consumptionthan on engines with port injection.

Technical data Deka DI XL2 injector:

Working flow range: > 20

Static flow: 5 to 17 g/s (10 MPa, 70°C)

Minimum dynamic flow: < 4 mg/stroke

SMD size: ~ 22 µm

Injections per cycle: up to 2

Opening/closing time: ≥ 300 µs

System pressure: 4 to 12 MPa (15 MPa optional)

Mounting position: Side position,

(central position optional)

Spray patterns: Swirl (Cone angle: 35° to 80°,bent angle: 0 to 25°)

Multi stream (Cone angle: 35° to 90°,bent angle: 0° to 30°)

Deka DI XL2 injector

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New design for more performance

Our new Deka DI XL2 solenoid-actuated in-jector delivers the versatility required forvariable injection. Because of its enhancedlinearity, this injector is perfect for use inturbocharged engines.

With 22 µm (SMD) at the maximum injec-tion pressure of 15 MPa, the fuel atomiza-tion quality is thus ideal for efficient com-bustion. Very fast opening and closingtimes and different nozzles for swirl or mul-ti-stream spray geometry enable optimaladaptation to specific engine requirements.The injector can be integrated into the fuelrail either by a metal-to-metal connection or

a conventional O-ring. The Deka DI XL2 is al-so suitable for use with the wide range offuel grades encountered all over the world.

With its many attractive properties, precis-ion control, and versatile integration opt-ions, our Deka DI XL2 is ideal for deploy-ment in engines with homogeneous directinjection, with or without turbocharging.

Deka DI XL2 swirl: nozzle and spray pattern Deka DI XL2 multi stream: nozzle and spray pattern

High-pressure pump

Technical data high-pressure pump:

Flow: up to 170 kg/h at 3,500 rpm

(depending on the number

of pistons 2...6)

Maximum fuel pressure: up to 20 MPa

Supply pressure: 0.45 to 0.6 MPa

Flow control valve: PWM signal, 0 to 2 A,12 V,

200 Hz

Operating Temperature: –40° to 130°C

High-pressure pump –precise and efficient

To complement our piezo and solenoid di-rect injection systems, we have developed anew high-pressure pump. Although basedon the current generation of pumps, it feat-ures even greater flow control accuracy anda particularly low drive torque.

Low power requirement =high efficiency

The pump generates fuel pressures of up to20 MPa and works on the transfer principle.All the moving parts are contained in an oilbath, which is separated from the fuel systemby a stainless steel diaphragm. This minimizesthe drive torque while simultaneously pre-venting oil contamination of the fuel.

Multiple installation options,maximum design freedom

The pump offers excellent high-pressuredelivery rates, even on cold starts, becauseof the choice of a multi-piston system. De-livery rates can be adapted to the require-ments of a specific engine by scaling be-tween two and six pistons.

The pump incorporates a safety valve andcan also be fitted with an optional by-passvalve for low-pressure starting.

Additional innovative componentsfor direct injection systems

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NOx sensor

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Technical data NOx sensor:

Triple output signal (NOx, linear l, binary l)

Measuring range: NOx: 0 to 500 ppm or 0 to 1,500 ppm

lin. l: 0.75 to air

bin. l: > 0.75 V at l=0.9; < 0.2 V at l=1.1

Accuracy: NOx: 100 to 500 ppm: ± 10%; 0 to 100 ppm: ± 10 ppm

lin. l: at l=1: ±6 (1000/l) new

bin. l: 1.002 ± 0.008 l

Response time (33-66%): NOx: 750 ms

lin. l: 550 ms

bin. l: 100 ms

CAN communication: standard (500 kbaud, 11bit), extended (250 kbaud, 29bit)

The pump can be driven directly off thecamshaft or by a belt if side mounting ischosen. This provides maximum freedomand multiple installation options to suit anyengine layout.

NOx sensor – storage catalysts undercontrol

Our smart NOx sensors help automotivemanufacturers meet ever stricter emission

regulations and further reduce fuelconsumption. This type of sensor measuresthe concentration of NOx, while alsoproviding a linear and binary lambdameasurement signal.

These sensors are essential for themanagement and diagnosis of the NOxstorage catalysts that will allow gasolineengines with stratified combustion to meetdemanding new emission regulations suchas Euro 5 and SULEV.

Tried and true –port injection

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Technical data Deka VII injector:

Working flow range: > 12

Static flow: 0.95 to 6.0 g/s (100-600 kPa, 20°C)

Minimum linear pulse: 1.10 to 1.40 ms

SMD size: ~60 to 100 µm with ASQUAREDTM atomization

Opening/closing time: opening < 1 ms

closing < 0.7 ms

System pressure: 100 to 600 kPa

Mounting position: Manifold or cylinder head port

Possible spray patterns: Cone spray: 10° to 30°

Bent stream: 5° to 25°

Split stream: 15° to 30°

Bent/split stream: combination of above

Despite the many benefits of direct injection,port injection (or multi-point injection – MPI)with external mixture preparation will contin-ue to be the dominant global technology inthe high-volume segments of the market be-cause its cost-benefit ratio remains unrivaled.

Ultra-fine atomization throughASQUAREDTM technology

Our Deka VII injectors have been developedspecifically for this type of engine. Theybuild on the proven Deka IV generation butallow more flexible packaging, feature anextended range of operation, and are alsolighter. These benefits give Deka VII inject-ors a major advantage with regard to meet-ing future emission standards such as Euro 5

and SULEV. Thanks to our innovativeASQUAREDTM atomization technology,SMDs of less than 60 µm can be achieved,depending on fuel pressure and the orificedisc calibration. Such extremely fine atomi-zation improves the combustion process,thereby reducing emissions.

Deka VII injector family

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Deka VII –flexibility to suit every application

Versatility is another key property of thenew Deka VII injectors. All three bodylengths can be combined with each of thethree nozzle length options while retainingidentical characteristics. A wide range ofspray forms can also be produced to suitcomplex intake manifold geometries. Inturn, this allows greater freedom in intake

manifold design and reduced wall wetting.Benefits include the potential to reduce HCemissions, particularly in the cold-startphase.

These injectors also represent a major stepforward in terms of linearity. Depending oncalibration, they provide linear injectionperformance even with short injection puls-es from 1.2 ms, minimizing the impact ofthe injector’s opening and closing behavior.

We also offer intelligent module solutionswith pre-assembled injectors. These solut-ions are individually matched to customer-specific engine requirements.

Deka VII injector: nozzle and spray pattern

There is a growing market for alternative fu-els, with rising oil prices leading to particularinterest in natural gas and LPG systems.Many countries provide tax breaks for bothgaseous compressed natural gas (CNG) andliquefied petroleum gas (LPG), meaning thatthese alternative fuels are sometimes con-siderably cheaper than gasoline or diesel.

Gas-powered engines also have good envi-ronmental credentials. Compared to an en-gine running on gasoline, they emit up to75% less carbon monoxide, up to 60% fewerhydrocarbons, and up to 25% less carbon di-oxide.

As a result, there are currently some500,000 gas-powered vehicles in use in Eu-rope, with numbers increasing all the time.However, due to restricted availability of al-ternative fuels, customers are extremely re-luctant to buy “monovalent” vehicles thatrun exclusively on gas. The majority of vehic-

les are bi-fuel models where the driver canswitch between gasoline and gas.

New solutions for a growing market

To meet the increasing demand for vehiclespowered by alternative fuels, manufactur-ers and suppliers need flexible, attractivelypriced solutions that meet a wide range ofcustomer and market requirements.

In terms of engine management, for exam-ple, the use of natural gas requires modifi-cations to the mixture formation control.Our approach is to offer automotive manu-facturers total flexibility, giving them thechoice between developing new hardwareand software based on the existing enginemanagement system or incorporating anauxiliary control unit via the CAN interface.

The gas-specific part of the ECU or the auxili-ary control unit follow a generic design andcontain the functions for operating addi-tional actuators, signal detection from addi-tional sensors for diagnostics of natural gascomponents, and switching between thetwo different fuels in bi-fuel operation. Inboth cases, the flexible system design al-lows the versatile integration of natural gascomponents of different types, whicheverinjectors, sensors, solenoid valves, or tanksare used.

A universal modular systemfor alternative fuels

The other function modifications requiredfor natural gas operation, e.g. injection, ig-nition, lambda control, and on-board diag-nosis, take place within the context of theexisting software for gasoline operation.These enhancements can also be used inconjunction with alcohol-based fuels suchas bio-ethanol.

This strategy enables us to create a highlyversatile modular system that allows auto-motive manufacturers to react quickly, flexi-bly, and cost-effectively to new market de-velopments, fuel trends, and the legalrequirements.

Flexible savings – with alternative fuels

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CNG injector LPG injector

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Siemens VDO Automotive AGGasoline SystemsSiemensstrasse 1293055 RegensburgPhone: +49 (941) 790-0www.siemensvdo.com

The information provided in this brochure contains only general descriptions or perfor-

mance characteristics, which do not always apply as described in case of actual use or

which may change as a result of further development of the products. An obligation to

provide the respective characteristics shall only exist if expressly agreed in the terms of

contract. We reserve the right to make changes in availability as well as technical changes

without prior notice.

J71001-A-A654-X-7600 | 09.2005 | English © 2005 Siemens VDO Automotive AG

Printed in Germany