Siemens Aktiengesellschaft

Continental Automotive Gmbh

Vitesco Technologies Gmbh

Oliver Kastner

Rolf Brück

Gerd Rösel

Hans-Peter Rabl

Roland Dietl

Andreas Weigand

Frank Atzler

Oliver Maiwald

To reduce pollutant emissions and consumption of passenger cars diesel engines multiple injection strategies are applied. Assuming constant cylinder and bowl geometry and constant rail pressure the variation of the number of injections, injection quantity of each injection and separation between two consecutive injections are the major parameters to be optimised. Furthermore, a single injection is applied with a shaped injection rate by a rise in injection pressure, equal to that observed in cam controlled injection systems. The needle lift can be modified for piezo driven common rail injection systems. Both methods are compared in terms of pollutant emission, fuel consumption and robustness. Experiments were carried out on single cylinder research engines. Multiple injection strategies with large hydraulic dwell times were compared with a short dwell setting simulating a 'rate shaped' single injection. Rate shaping was implemented performing multiple injections with hydraulic dwell times close to or equal zero.

Method for reducing pollutant emissions and consumption of an engine

In a method for equalizing the differences in injection quantities between the cylinders of a combustion engine, an adaptation of the differences in injection quantities, of the injection curves and of the hydraulic start of injection is carried out for different operating points of the combustion engine for at least one selected injection parameter. During this adaptation, the dynamics of a selected operating point are limited. The differences in injection quantities are determined for this selected operating point and are learned as adaptation values that are assigned to the respective injection parameter. In order to limit the dynamics, the injection parameter is set so that the selected operating point remains essentially stationary.

Method for balancing out the differences in the injection quantities between the cylinders in an internal combustion engine

In a method for enlarging the control range for equalizing injection quantity differences, in particular in internal combustion engines using multiple injections, if the maximum injection quantity of all the individual injections of an injector of the internal combustion engine is lower than the minimum quantity required for control for equalizing the cylinders, then the injection pattern is changed such that the injection quantity of at least one individual injection is greater than or equal to the required minimum quantity, without changing the torque output of the internal combustion engine.

Method for enlarging the control range for equalizing injection quantity differences

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Donaustauf, Germany

Oliver Kastner