Patent ID: 8593162

Claim:
A fuel-aspect sensor for detecting aspects of mixed fuel, which is mixture of different fuels respectively having different specific inductive capacities, comprising: a first housing member having a fuel chamber through which the mixed fuel flows and an insertion hole for communicating the fuel chamber with outside of the first housing member, the insertion hole having an open end at which a stepped portion is formed; a first electrode inserted into the insertion hole from the open end of the insertion hole, the first electrode having an inside space being in communication with the fuel chamber, the first electrode having a flanged portion extending in a radial direction of the first electrode so that the flanged portion is inserted into the stepped portion of the insertion hole; a second electrode having a closed bottom portion, a lower part of the second electrode being accommodated in the inside space of the first electrode, so that an outer surface of the second electrode is exposed to the mixed fuel introduced into the inside space of the first electrode; an insulating member for electrically insulating the first and second electrodes from each other and for firmly fixing the first and second electrodes to each other; a temperature sensor accommodated in the second electrode and fixed to an inside surface of the closed bottom portion thereof for detecting temperature of the mixed fuel; a second housing member firmly attached to the first housing member for closing the open end of the insertion hole of the first housing member; an electronic control unit accommodated in the second housing member and electrically connected to the first electrode, the second electrode, and the temperature sensor, for detecting electrostatic capacity between the first and second electrodes, to thereby detect the aspects of the mixed fuel based on the electrostatic capacity and the temperature of the mixed fuel; and an elastic member disposed between the second housing member and the first electrode for biasing the flanged portion of the first electrode toward a sealing surface of the first housing member, which is formed at an inner wall of the insertion hole , so that the flanged portion is in contact with the sealing surface, wherein a diameter of the elastic member is larger than that of the flanged portion of the first electrode, wherein the stepped portion comprises a first vertical surface, a first stepped surface, a second vertical surface, and a second stepped surface, and wherein the flanged portion comprises a first diameter portion and a second diameter portion, in which the second diameter portion is larger than the first diameter portion.