Patent ID: 8428808
Filing Date: 2013-04-23
Classification: B60W,F02D,F16H,Y02T

Abstract:
1. An engine fuel diagnosis device for diagnosing whether an unexpected fuel is being used in an internal combustion engine, the unexpected fuel being a fuel in which changes in fuel components go beyond an expected range, the device comprising: an inclination detecting section that, when a vehicle on which the internal combustion engine is mounted is traveling uphill or downhill, is configured to detect the inclination of the road surface; a first estimating section configured to compute a first estimated acceleration, which is a vehicle acceleration obtained when fuel injection is executed in the internal combustion engine while the vehicle is traveling uphill or downhill, based on an engine power, which is estimated based on the engine speed and the engine load on the assumption that a previously expected fuel is being used, and the inclination detected by the inclination detecting section; an acceleration detecting section configured to detect an actual acceleration, which is the actual acceleration of the vehicle; a diagnosing section configured to compute a first deviation degree indicating the degree of deviation between the first estimated acceleration and the actual acceleration detected when the first estimated acceleration is computed, and configured to diagnose a usage state of the unexpected fuel based on the first deviation degree; and a second estimating section configured to compute a second estimated acceleration based on the inclination detected by the inclination detecting section, the second estimated acceleration being a vehicle acceleration obtained when fuel injection is off in the internal combustion engine while the vehicle is traveling uphill or downhill, wherein the diagnosing section is configured to compute a second deviation degree indicating the degree of deviation between the second estimated acceleration and the actual acceleration detected when the second estimated acceleration is computed, and is configured to correct the first deviation degree based on the second deviation degree when diagnosing the usage state of the unexpected fuel.