Diagnostic system for detecting faults in engine air intake check valves
US5138874A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1991 |
| Grant date | Aug 18, 1992 |
| Priority date | — |
| Expiry date | Jul 1, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A system is disclosed for diagnosing faulty check valve operation in an internal combusiton engine having a back flow preventing check valve positioned in each intake air passage leading to an engine cylinder. The system measures the pressure in the engine air induction system, upstream of each check valve and downstream from an air intake throttle valve. The system produces an indication of faulty check valve operation, when an abnormal fluctuation in the measured pressure is detected. Preferably, the diagnostic function is performed when the engine operates in a defined mode, at idle speeds with light engine loading, where the pressure differential appearing across each check valve is essentially maximized. The engine cylinder associated with a faulty check valve is identified based upon the sensed rotational position of the engine when an abnormal fluctuation in pressure is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.