Compression ratio mode selection logic for an internal combustion engine having discrete variable compression ratio control mechanism
US6970781B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 2004 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | Jun 3, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A method and system for operating an internal combustion engine. The internal combustion engine is operable in a plurality of compression ratio operating modes. The method includes determining a relationship between a base engine threshold load where the high compression and low compression provide substantially the same engine fuel consumption and engine speed. The determined nominal relationship is modified by a factor, such factor being a function of a condition under which such engine is operating, to obtain a modified relationship. The modified relationship is a function of engine speed and the condition has an effect on knock generation in such engine. The modified relationship and engine speed are used in selecting one of the plurality of compression ratio operating modes for the engine. A hysteresis load as a function of engine speed is determined and applied to the determined hysteresis load to the modified relationship to inhibit switching oscillations between a pair of the plurality of compression ratio operating modes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.