Abnormality detection device for internal combustion engine

摘要

The present invention provides an abnormality detection device in which the fuel property sensor is disposed in a branch flow path which is such that there is a time where the fuel in the branch flow path drops out therefrom between one start of the internal combustion engine and the next start. An output value of the fuel property sensor generated when the fuel is flowing through the branch flow path is acquired as a first sensor output value. An output value of the fuel property sensor generated when the fuel in the branch flow path drops out therefrom is acquired as a second sensor output value. The first sensor output value and the second sensor output value are used as judgment data to judge whether the fuel property sensor is abnormal.

主权项

1. An abnormality detection device for an internal combustion engine whose operation is controlled in accordance with properties of an employed fuel, the abnormality detection device comprising:
a branch flow path branched off from a primary flow path of a fuel flow path connecting a fuel pump to an injector, the branch flow path being such that there is a time where the fuel in the branch flow path flows out between a start of the internal combustion engine and the next start following a stoppage of the internal combustion engine; a fuel property sensor disposed in the branch flow path, the fuel property sensor generating different output values depending on whether a liquid or a gas exists in a measurement section, and when a fuel exists in the measurement section, the output value is determined in accordance with the properties of the fuel; first sensor output value acquisition means for acquiring a first sensor output value of the fuel property sensor, the first sensor output value being an output value generated by the fuel property sensor in a situation where the fuel is flowing through the branch flow path; second sensor output value acquisition means for acquiring a second sensor output value of the fuel property sensor, the second sensor output value being an output value generated by the fuel property sensor in a situation where the fuel in the branch flow path has flown out; and abnormality judgment means for checking for an abnormality in the fuel property sensor by using the first sensor output value and the second sensor output value as abnormality judgment data.