Robert Boschgmbh

Hans Barho

Helmut Denz

Michael Lehner

Andrea Lohmann

Helmut Gross

Robert Seyfang

Martin Bulla

A method for detecting combustion misses in a multi-cylinder internal combustion engine. The control units of the engine use an engine control program which is interrupted by interrupt routines, in phase-synchronism with the rotational movement of the crankshaft, in which at least the data required for injection and firing are processed. The detection of combustion misses includes establishing and evaluating crankshaft segment times in which the crankshaft covers an associated circle-segment angle range. The crankshaft segment are also established and evaluated in particular interrupt routines, and for the further subset of cylinders in the interrupt routines in which their firing is controlled. Furthermore, the crankshaft segment times for the first cylinder is established and evaluated in certain additionally generated interrupt routines.

Method for detecting misfiring in a multi-cylinder internal combustion engine

Disclosed is a multi-cylinder internal combustion engine in which a group of cylinders is disconnectable in dependence on one or more operational parameters of the engine. The connection or disconnection of the groups of cylinders occurs in response to an engine load variation, to an acceleration signal or to a deceleration signal and to the engine temperature. The switchover takes place within a predetermined time interval. During the switchover of the cylinder groups, the ignition angle and if desired the volumetric efficiency are controlled. When only a part of the cylinders of the engine is in operation after a predetermined number of engine rotations the active cylinders are disconnected and simultaneously the inactive cylinders are connected into operation. During the switchover process any unintentional switchover is prevented by a signal blocking device. A stabilization of idling speed of the engine is selectively made by connecting into operation a group of cylinders or by an auxiliary air flow device. The switchover of cylinder groups during a partial load operation is influenced by switching devices having hysteresis behavior, which also enhances the stabilization during idling operation. The engine of this invention is preferably used in all kinds of motor vehicles.

Multi-cylinder internal combustion engine having disconnectable groups

An electronically controlled fuel metering system for an internal combustion engine, in which a multiplicative correction is made during warmup and acceleration in accordance with the formula

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Stuttgart, Germany

Hans Barho