Fault detection method and system for exhaust gas recirculation system
US5474051A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1994 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Aug 30, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M26/53
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A fault detection system is provided for an exhaust gas recirculation (EGR) system. The fault detection system is constructed of an engine operation state detection device, an EGR valve opening/closing device, and a system operation fault detection device. The engine operation state detection device is provided with an air flow sensor arranged in an intake passage on an upstream side of a throttle valve, and detects the engine operation state that the pressure difference between a pressure within an intake passage on a downstream side of the throttle valve and a pressure within the intake passage on an upstream side of the throttle valve is not greater than a critical pressure. Upon detection of the above engine operation state, the EGR valve opening/closing device opens or closes an EGR valve. When a change in the output from the air flow sensor between before and after the opening or closing of the EGR valve is detected to be smaller than a predetermined fault determination value, the system operation fault detection device detects that the EGR system is not operating properly. A fault determination zone is set by avoiding a critical pressure operation zone, so that a fault in th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.