Vehicle Diesel Engines
The diesel engine came to be used as a car engine relatively late after the first demonstration of its operation in 1897. The introduction of the first mass produced diesel passenger cars in 1936 finally enabled diesel engines to vie with the dominant gas
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Vehicle Diesel Engines Fritz Steinparzer, Klaus Blumensaat, Georg Paehr, Wolfgang Held, and Christoph Teetz
17.1
Diesel Engines for Passenger Cars
17.1.2
Specific Vehicle Requirements
17.1.1
History
17.1.2.1
Quality Criteria
The diesel engine came to be used as a car engine relatively late after the first demonstration of its operation in 1897. The introduction of the first mass produced diesel passenger cars in 1936 finally enabled diesel engines to vie with the dominant gasoline engines of the day as an alternative drive concept in this segment too. The stage for this had been set by the highly precise fuel metering timing allowed by the injection systems Bosch had started developing and manufacturing (1927) and the control of the processes of mixture formation and combustion at relatively high engine speeds by dividing the combustion chamber into a prechamber and main chamber, an idea that dated back to L’Orange. Driven by the increasing focus on energy saving propulsion sources that conserve resources and reduce climatically relevant CO2 emissions toward the end of last century, diesel engines repeatedly experienced reasonable successes in cars but never truly established themselves. The real breakthrough came in the second half of the 1990s when new high pressure injection systems such as unit injector systems and, above all, common rail injection technology became available as standard, thus enabling a changeover to direct injection and the development of innovative exhaust gas turbochargers with variable turbine guide blade systems. These new technologies made it possible to tremendously improve the performance characteristics of diesel cars, which are relevant to customers. Figure 17-1 highlights this impressive development of power, torque, fuel consumption and emission performance.
G. Paehr (*) Volkswagen AG, Wolfsburg, Germany e-mail: [email protected]
As car engines, diesel engines are conceptually interrelated to vehicles by various subsystems (transmission, chassis, etc.) in a variety of ways. Therefore, the design requirements for a driving engine must be derived from a vehicle’s general quality criteria and aspects of the drive train – essentially the design and characteristics of the transmission employed. In terms of product features, the basic vehicle requirements are based on criteria such as transportation performance, safety, comfort, operational safety and environmental compatibility. The individual categories can be broken down into secondary aspects from which the criteria relevant for an engine can be derived. The functional requirement of transportation performance addresses vehicle performance, energy input and energy conversion. Vehicle safety requirements also have consequences for the drive train. For instance, they affect: – engine responsiveness and the controllability of engine power, – transmission of driving torque on the road or even – suitable limp-home strategies in a fault scenario. Fire resistance is also an important aspect of engine design. The comfort r
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