Diagnostic for engine cam profile switching system
US9188075B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 2012 |
| Grant date | Nov 17, 2015 |
| Priority date | — |
| Expiry date | Jan 2, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A momentary diagnostic for determining correct operation of a cam profile switching system of an internal combustion engine by calculation of changes in cylinder bank to bank air mass flow ratios: operating said engine in one condition of the cam profile switching system; providing for a first cylinder subset the inlet fuel flow and the corresponding oxygen content of the exhaust flow, and calculating the mass of air passing through the first cylinder subset in a defined time period; providing for a second cylinder subset the inlet fuel flow and the corresponding oxygen content of the exhaust flow; calculating the mass of air passing through the second cylinder subset in said defined time period; comparing the mass air flow the oxygen content for the first and second cylinder subsets to give a standard ratio; momentarily forcing the cam profile switching system of one of said cylinder subsets to an alternative condition; re-calculating providing the corresponding mass of air oxygen content passing through the first and second cylinder subsets; and comparing said recalculated air flows oxygen contents to give a revised ratio; and comparing said standard ratio and revised ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.