Patents by Inventor Kiyohiro Miyamoto

Kiyohiro Miyamoto 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).

  • Steel workpiece oil quenching method
    Patent number: 6723188
    Abstract: A steel workpiece maintained at a specified quenching temperature is rapidly cooled to a temperature just above the martensite transformation start point (Ms point) by being immersed in a high-temperature quenching oil. Thereafter, the steel workpiece is taken out of the high-temperature quenching oil so as to be soaked by the heat possessed by the steel workpiece and subsequently cooled by being immersed in the high-temperature quenching oil. Through these processes, a temperature difference between steel workpieces or the portions of a steel workpiece in the martensite transformation stage is reduced, and a cooling speed in a high-temperature region (not lower than about 550° C.) is made to be a slow speed sufficient for restraining a thermal distortion, by which the quenching distortion and quenching variation can be reduced.
    Type: Grant
    Filed: February 7, 2002
    Date of Patent: April 20, 2004
    Assignee: Chugai Ro Co., Ltd
    Inventors: Yoshikazu Shimosato, Saburo Ogawa, Kiyohiro Miyamoto
  • Steel workpiece oil quenching method
    Publication number: 20020166610
    Abstract: A steel workpiece maintained at a specified quenching temperature is rapidly cooled to a temperature just above the martensite transformation start point (Ms point) by being immersed in a high-temperature quenching oil. Thereafter, the steel workpiece is taken out of the high-temperature quenching oil so as to be soaked by the heat possessed by the steel workpiece and subsequently cooled by being immersed in the high-temperature quenching oil. Through these processes, a temperature difference between steel workpieces or the portions of a steel workpiece in the martensite transformation stage is reduced, and a cooling speed in a high-temperature region (not lower than about 550° C.) is made to be a slow speed sufficient for restraining a thermal distortion, by which the quenching distortion and quenching variation can be reduced.
    Type: Application
    Filed: February 7, 2002
    Publication date: November 14, 2002
    Inventors: Yoshikazu Shimosato, Saburo Ogawa, Kiyohiro Miyamoto