Patents by Inventor Keiichi Yagisawa

Keiichi Yagisawa 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).

  • Exhaust gas purifying apparatus for internal combustion engine and controller for internal combustion engine
    Patent number: 6327849
    Abstract: When deterioration of a NOx purifying device due to sulfur contamination is detected, a specific operating state flag FHL is set to “1,” and, at intervals equal to or shorter than, for example, three seconds, the air-fuel ratio of an air-fuel mixture to be supplied to an engine is varied so that it is alternately leaner and richer than the stoichiometric air-fuel ratio. When the temperature TCAT of the NOx purifying device exceeds a deterioration recovery temperature STCAT2 while the air-fuel ratio variation control is being executed, the SOx removing flag FHLSOx is set to “1,” and for a period equivalent to the deterioration recovery time TRSOx, the air-fuel ratio is maintained richer than the stoichiometric air-fuel ratio.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: December 11, 2001
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Kenji Sugiura, Hiroshi Ohno, Masahiro Sakanushi, Keiichi Yagisawa