Engine control for enhanced catalyst warm up while maintaining manifold vacuum
US5497745A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 1995 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Feb 24, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An engine controller (12) controls an ignition system (88) and bypass throttle valve (96). An ignition timing signal is set to an initial value as a function of engine (10) operating parameters. The timing signal is retarded during cold operation to rapidly warm a catalyst converter (20) coupled to the engine exhaust (48). When the vacuum in the intake manifold (44) falls below a threshold level, the ignition timing signal is advanced beyond the initial value. The ignition timing signal is retarded back towards its initial value when the manifold vacuum exceeds the threshold value. Concurrently, the initial timing signal is controlled to achieve desired engine idle speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.