Multi-cylinder internal combustion engine having disconnectable groups of cylinders

US4550704A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hans Barho · Bad Dürrheim, DE
• Helmut Denz · Stuttgart, DE

Key dates

• Filing date: Mar 19, 1984
• Grant date: Nov 5, 1985
• Expiry date: Mar 19, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

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…