Daimler Chrysler Ag

Daimler Ag

Martin Dietz

Christian Barba

Guenter Moll

Siegfried Sumser

Peter Fledersbacher

Gernot Hertweck

Erhard Steffen

Bernd Lindemann

In an engine braking method and an internal combustion engine including an engine braking arrangement, wherein the engine has high pressure and low pressure exhaust gas turbochargers connected in series, with a bypass () around the high-pressure compressor allowing the air mass flow selectively to bypass the high pressure compressor which is arranged near the engine, and bypasses around both turbines permitting the exhaust gas mass flow selectively to bypass the high-pressure exhaust gas turbine which is near the engine and also the low pressure turbine the intake air and the exhaust gas flow are controlled so as to accurately provide for a desired engine braking power for example for maintaining a desired vehicle speed.

Engine braking method for an internal combustion engine having two serially arranged exhaust-gas turbochargers

In a method for determining the exhaust-gas recirculation quantity for an internal combustion engine having exhaust-gas recirculation, a basic quantity of a gas mixture inducted into the engine combustion chamber(s) is determined in advance, as well as a basic pressure and/or a basic temperature of the gas mixture for at least one predefinable basic state of the combustion engine at deactivated exhaust-gas recirculation is ascertained. With the engine running, pressure and/or temperature of the inducted gas mixture are/is then determined for the current engine state at activated exhaust-gas recirculation. The currently inducted gas-mixture quantity as the basic quantity is then corrected by at least the ratio of current pressure to basic pressure of the gas mixture and/or the ratio of basic temperature to current temperature of the gas mixture. Furthermore, a fresh-gas portion of the inducted gas mixture for the current engine state is ascertained, whereupon the current exhaust-gas recirculation quantity is determined on the basis of the difference between the ascertained current gas-mixture quantity and the ascertained fresh-gas portion. The method may used in connection with diesel engines of motor vehicles, for example.

Method for determining the exhaust-gas recirculation quantity

In a method for determination of a change in volumetric efficiency for an internal combustion engine, a reference volumetric efficiency is determined in advance. A first actual volumetric efficiency value which corresponds to a sensor error, is then determined at a first measurement point in a first rotational speed range in which a change in the flow losses in an intake tract has only a minor effect on the volumetric efficiency. A second actual volumetric efficiency value is determined at a second measurement point in a second rotational speed range that is greater than the first rotational speed range. The second actual volumetric efficiency value is corrected by means of the first actual volumetric efficiency value, and the change in volumetric efficiency is determined from the reference volumetric efficiency and the corrected second actual volumetric efficiency.

Method for determining a change in air consumption for a combustion engine

In a method of determining the quantity of exhaust gas recirculation for an internal combustion engine having exhaust gas recirculation, the exhaust gas recirculation quantity (r, m) is determined from an exhaust gas temperature (T), a fresh gas temperature (T), a fresh gas quantity (m) and/or a volumetric efficiency (&#x3b7;). The fresh gas temperature (T) is determined by a fresh gas temperature model () which is adaptively adjusted in response to influencing parameters relevant to the fresh gas temperature.

Method for determining an exhaust gas recirculation quantity for an internal combustion engine provided with exhaust gas recirculation

In a process for determining the opening time of an injection valve of a common-rail injection system, an injection duration is derived from a characteristic diagram based on the fuel quantity to be injected and the static pressure in the common rail. For reading in the characteristic diagram, the value of the static pressure in the common rail is corrected by an amount obtained from the compressional vibration of the fuel as a function of its compressibility, the injected fuel quantity during at least one preceding injection operation, and the time between the at least one preceding injection operation and the current injection operation.

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Stuttgart, Germany

Martin Dietz