Abnormality detection device for fuel property detection device

Abstract

In order to accurately diagnose the abnormality of a fuel property detection device for detecting the fuel property on the basis of the capacitance between electrodes, disclosed is an abnormality detection device for a fuel property detection device. Said abnormality detection device is a device for detecting the abnormality of the fuel property detection device for detecting the fuel property on the basis of the measured value of the capacitance between a pair of electrodes installed in a fuel supply path of an internal combustion engine that can use fuel containing a predetermined fuel component having a characteristic that the dielectric constant changes according to the frequency of an electric field, said abnormality detection device being characterized by being provided with: a frequency switching means which switches the frequency of alternating voltage to be applied between both the electrodes to a plurality of frequencies; a measurement means which measures the capacitance at each of the plurality of frequencies; a storage means which stores frequency characteristic information that is information relating to the relationship between the fuel property and the frequency characteristic of the capacitance when the fuel property detection device is normal, and a diagnosis means which, on the basis of the result of the measurement by the measurement means and the frequency characteristic information, diagnoses the abnormality of the fuel property detection device.

Description

technical field [0001] The present invention relates to an abnormality detection device of a fuel property detection device. Background technique [0002] A mixture of fuel (such as ethanol) produced from biomass (biomass) and conventional fuel (such as gasoline) is used in internal combustion engines such as automobiles. Gasoline and ethanol have different fuel characteristics such as theoretical air-fuel ratio and calorific value. Therefore, the characteristics of ethanol-gasoline blends vary according to the concentration of ethanol. Therefore, in order to properly control the internal combustion engine when ethanol-gasoline mixed fuel is used, a device for detecting the ethanol concentration of the fuel is required. As a device capable of detecting the ethanol concentration of fuel, a capacitive fuel property detection device is known. The capacitive fuel property detection device has a pair of electrodes provided on a fuel supply path, and measures the capacitance be...

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Problems solved by technology

[0011] In addition, for fault diagnosis, a method of providing a pair of reference electrodes is also considered, but there are problems such as the complexity and size of the sensor structure and the increase in cost.

In addition, since abnormalities such as accumulation of rubber components and generation of rust also occur on the reference electrode, there is still a problem that accurate fault diagnosis may not be possible even when compared with the reference electrode.

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