Knock sensing apparatus for internal combustion engine
US5522254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1994 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Nov 29, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L23/225
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A knock sensing apparatus for an internal combustion engine which can detect a failure in a knock sensor signal system correctly even when a changeover operation due to hardware is performed at a place between a knock sensor and a band pass filter. In this knock sensing apparatus, the failure detection by a failure detecting circuit for detecting a failure in a signal system from knock sensors is invalidated for a predetermined period after one of the knock sensors has been changed over to the other knock sensor, or one of two kinds of pass bands of a band pass filter has been changed over to the other pass band, to prevent a decrease in failure detection accuracy due to the signal delaying action of the switched capacitor filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.