Robert Boschgmbh

Axel Stuber

Ernst Wild

Manfred Pfitz

Bernd Heppner

Wolfgang Richter

Eberhard Schnaibel

Lutz Reuschenbach

Erich Schneider

Nikolaus Benninger

Hans Veil

Martin Haussmann

Claus-Dieter Nusser

Joerg Kerner

Guido Ehlers

Peter Henkelmann

Hartmut Kischel

Bernd Landes

A method for diagnosing an exhaust-gas recirculation system of an internal combustion engine provides that the fuel quantity, which is needed for a desired mixture composition, is computed, at least approximately, in a control apparatus from at least stored data of the EGR system. The stored data can be in the form of a through-flow characteristic line. Thereafter, the fuel quantity is corrected by a control factor in dependence upon the mixture composition. The control factor is computed and stored when the EGR system is switched on and the control factor is computed and stored when the EGR system is switched off. The difference of these control factors is then formed and compared to pregiven values. A fault signal is outputted in the event of a deviation.

Method for diagnosing an exhaust-gas recirculation system of an internal combustion engine

Method and device for controlling an internal combustion engine in accordance with operating parameters

Fuel dosage control process for internal combustion engines

A device and method for controlling the amount of fuel supplied to an internal combustion engine as a function of operating characteristics such as the pressure in the intake manifold, the engine speed, coolant temperature and intake air temperature, where a load signal formed from pressure and engine speed values is corrected by a correction factor F.sub.CORR as a function of the temperature, and when forming the correction factor F.sub.CORR, the influences of the engine temperature and/or the intake air temperature on the load sensing are weighted separately as a function of the operating point.

Device and method for controlling the amount of fuel supplied to an

The invention is directed to a method for determining a load signal of an internal combustion engine having an intake pipe with a pressure sensor, external exhaust-gas recirculation (EGR) and an EGR valve. A load signal (tl) is computed in a circuit arrangement which is proportional to the mass inducted per revolution of the engine. The computation is made in dependence upon measured intake-pipe pressure (ps) and the speed (n) of the engine in rpm. On the one hand, the method makes a simple adaptation possible, while, on the other hand, a correct load signal is formed also in steady-state operation and, in this way, reduced exhaust-gas emissions of the engine are made possible. The exhaust-gas mass flow flowing through the EGR valve is determined by converting the exhaust-gas mass flow into an rpm-dependent signal. The rpm-dependent signal is filtered in a filter simulating charging operations in the intake pipe. A corrective signal (scorr) proportional to the exhaust-gas mass inducted by the engine per revolution thereof is determined and this corrective signal (scorr) is subtracted from the load signal (tl) to generate and output the corrected load signal (tlcorr).

Method for determining the load signal of an internal combustion engine

A method for monitoring the starting behavior of a catalytic conversion system by placing an apparatus in the exhaust-gas pipe of an internal combustion engine. The conversion power of the starting region can be determined from the temperature which results when an air/fuel mixture is fed to the catalytic conversion system.

Method and apparatus for monitoring the starting behavior of a catalytic

The invention is directed to a method for controlling the fuel quantity for an internal combustion engine having a catalytic converter and includes the steps of: determining the air mass flow inducted by the engine; determining a precontrol variable for the quantity of fuel in dependence on current values of operating variables of the engine; presetting a desired lambda value for the air/fuel mixture to be supplied to the engine; checking the actual lambda value of the exhaust gas forward of the catalytic converter; comparing the desired lambda value to the actual lambda value to form a comparison; controlling the fuel quantity in dependence upon the comparison; determining the oxygen actual charge level of the catalytic converter; comparing the determined actual charge level to a desired charge level; and, then, when the actual charge level is greater than the desired charge level, lowering the desired lambda value to below the value one; otherwise, when the actual charge level is less than the desired charge level, increasing the desired lambda value above the value one. This method leads to the condition that very low toxic exhaust gas is produced even for transient operations since the catalytic converter almost always has sufficient storage capacity for further oxygen which occurs temporarily or adequate oxygen for combusting fuel which occurs temporarily. The invention is also directed to an arrangement for carrying out the method.

Method and arrangement for controlling the quantity of fuel for an

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Tamm, Germany

Axel Stuber