Patents by Inventor Kazuaki Umezawa

Kazuaki Umezawa 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 recirculation system for an internal combustion engine
    Patent number: 5203311
    Abstract: Disclosed is an exhaust gas recirculation system for an engine having a high compression ratio or with a supercharger. An outside EGR duct connecting the exhaust system to the intake system is provided with a first control valve, which has a second outside EGR duct bypassing the first control valve. The second EGR duct has a second EGR control valve and a cooler. When the engine exists in an extremely low load state, the first and second control valves are closed to inhibit the outside EGR. In the light load state, the first control valve is opened while the second control valve is closed, thereby allowing recirculation of the EGR gases having high temperature and reducing the pumping loss.
    Type: Grant
    Filed: November 5, 1991
    Date of Patent: April 20, 1993
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Toshihiko Hattori, Kenji Kashiyama, Junsou Sasaki, Kazuaki Umezawa, Tadayoshi Kaide, Noriyuki Iwata, Naoyuki Yamagata, Kazumasa Nomura