Robert Boschgmbh

Carlos Koster

Georg Mallebrein

Juergen Pfeiffer

Federico Buganza

Kai Jakobs

Pierre-Yves Crepin

Emilie Hincker-Piocelle

Klaus Joos

Werner Haeming

Helerson Kemmer

Stephan Uhl

Oliver Miersch-Wiemers

The invention deals with a method for operating an internal combustion engine with engine oil as the lubricant, wherein a fuel mass flow outgassing from the engine oil is ascertained and is taken into account via a map-based pilot control during the metering of a quantity of fuel supplied to the internal combustion engine and wherein a fuel/air ratio supplied to the internal combustion engine is determined. Provision is made in the method according to the invention for a mass flow offset determined from the deviation of the fuel/air ratio supplied to the internal combustion engine from a nominal value to be taken into account when the metering of the quantity of fuel supplied to the internal combustion engine occurs during an effective duration of the map-based pilot control. The mass flow offset takes the deviation into account, which remained after the correction by a map-based pilot control of the quantity of fuel metered, on the basis of the modeled outgassing of fuel from the engine oil, and said mass flow offset balances the lambda controller in this way. The mass flow offset can by way of example have the effect of shortening the duration injection. The mixture deviations as a result of different boiling curves of the components of the fuel blend, which cannot be completely taken into account by the map-based pilot control under all operating conditions of the internal combustion engine, can in this way be compensated.

Method for taking the outgassing of fuel from the engine oil of an internal combustion engine into account

The invention deals with a method to determine the fuel composition of a fuel mixture from a first fuel and a second fuel for the operation of an internal combustion engine, wherein the first and the second fuel have different octane numbers and wherein the internal combustion engine has at least one knock sensor and a closed-loop knock control. Provision is made according to the invention for the composition of the fuel mixture to be determined by means of an output signal of the knock sensor. Provision is made in many cases for the knock sensor to already be in the internal combustion engine, so that it does not present any additional expenditure of money or effort. Because the octane number of the fuel mixture is determined by the mixing ratio of the fuels involved, which have different octane numbers, in retrospect the composition of the fuel mixture can be suggested from the signal of the knock sensor under suitable operating conditions.

Method to determine a fuel composition

The invention concerns a method to determine the composition of a fuel from the components ethanol and gasoline of an internal combustion engine, wherein the fuel is supplied to the internal combustion engine by a fuel supply unit and via two fuel distributor rails; and the exhaust gas is discharged from the internal combustion engine by two exhaust gas manifolds of a first and a second exhaust gas system, which are separated from each other, wherein the first and second exhaust gas system have in each case at least one exhaust gas probe and wherein current changes in the ethanol content of the fuel are evaluated from the signal differences of lambda signals from the exhaust gas probes. With this method, a change in the ethanol content of the fuel can be detected, and an explicit condition for a change in fuel can be derived. Moreover, with the method, errors in the fuel-mixture can be distinguished from an altered fuel composition, which takes place after the tank has been filled fueling.

Operation of an internal combustion engine with oil lubrication and electronic fuel injection, includes the steps of determining a flow of fuel mass (mkp_ausg) evaporating out of oil, and determining a setpoint injected-fuel quantity (rk_ev) with taking into account the determined flow of fuel mass.

Method for operating an internal combustion engine

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Campinas, Brazil

Carlos Koster