Patents by Inventor Masato Ujino

Masato Ujino has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Double air-fuel ratio sensor system having improved exhaust emission characteristics
    Patent number: 4817384
    Abstract: In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, an air-fuel ratio correction amount is calculated in accordance with the outputs of the upstream-side and downstream-side air-fuel ratio sensors, thereby obtaining an actual air-fuel ratio. The air-fuel ratio correction amount is guarded within a predetermined range. When this correction amount reaches the maximum or minimum value of the range, the calculation of the air-fuel ratio correction amount by the output of the downstream-side air-fuel ratio sensor is prohibited.
    Type: Grant
    Filed: August 11, 1987
    Date of Patent: April 4, 1989
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Atsuo Okumura, Masato Ujino, Takashi Kawase