Robert Boschgmbh

Emilie Hincker-Piocelle

Georg Mallebrein

Martin Streib

Pierre-Yves Crepin

Federico Buganza

Kai Jakobs

Juergen Pfeiffer

Carlos Koster

Klaus Joos

Werner Haeming

Helerson Kemmer

Jens Wolber

Ruediger Weiss

Karsten Kroepke

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 deals with a method for the operation of an internal combustion engine with at least two cylinders, which can be operated with a fuel of variable quality stored in a tank and/or with fuel blends stored in the tank from a first and at least a second fuel in variable mixing ratios, and wherein variable fuel qualities and/or fuel blends of different compositions require variable air/fuel ratios for the achievement of a stable combustion and/or have a variable vaporization behavior. Provision is, thereby, made for a variation, which is individually adjusted to each cylinder, of the quantity of fuel delivered to the cylinder to be implemented to supply a lean and/or to a rich air/fuel mixture at least one cylinder, for the effect of the variation on the starting characteristics and/or the running smoothness of the cylinder and/or the internal combustion engine to be evaluated and when an improvement in the starting characteristics and/or the running smoothness is achieved, for a fuel adaptation to be implemented for all cylinders. The method makes the quick detection and the avoidance of starting problems possible, when a change in the fuel quality or in the fuel composition occurs with an effect on the ignitability of the fuel.

Method for the operation of an internal combustion engine

Growing community of inventors

Ludwigsburg, Germany

Emilie Hincker-Piocelle