Method for cylinder cutout in an internal combustion engine

US5787855A · kind A · utility

Assignee

• Ing. h.c. F. Porsche Aktiengesellschaft · DE

Inventors

• Stephan Mueller · Leonberg, DE
• Dietmar Schwarzenthal · Ditzingen, DE

Key dates

• Filing date: Apr 19, 1996
• Grant date: Aug 4, 1998
• Expiry date: Apr 19, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A method for cylinder cutout in an internal combustion engine, with the engine having charge exchange valves on a portion of its cylinders. The charge exchange valves can be cut out as well as a switchable fuel supply, both of which can be switched from a cut-out or cut-off state to a cut-in state and vice versa. In order to provide a method for cylinder cutout that permits a safe transition from operation in which they are not cut out to one in which they are cut out, and by which the effects of cylinder cutout on fuel consumption and exhaust behavior are minimized, the fuel supply and the charge exchange valves may be cut out separately or in parallel. Before cylinder cutout, both the time required to cut out the charge exchange valves and the time required to cut off the fuel supply are calculated. Then these two times are compared and a waiting time is determined for the shorter process. When the next reference mark on the internal combustion engine is reached, both processes can proceed independently. The longer process is started immediately and the shorter process starts after the waiting time determined previously has expired.