Patents by Inventor Kiyoshi Wajima

Kiyoshi Wajima 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).

  • Patent number: 6337566
    Abstract: The present invention relates to a continuous casting apparatus for continuously casting molten metal. More particularly, the present invention provides a method and an apparatus for controlling a surface level of molten metal in a mold when molten metal is continuously cast. The continuous casting apparatus of the invention comprises: a mold in which molten metal is poured and solidified; and an eddy current type molten metal surface level sensor for detecting a molten metal surface level in the mold. In the continuous casting apparatus having an electromagnetic coil arranged in such a manner that the electromagnetic coil surrounds the mold and also having an electric power supply for generating a pulse magnetic field from the electromagnetic coil, there are provided a mechanism for taking out a pulse trigger signal corresponding to the magnetic field from the electric power supply, and a mechanism for controlling a time of detecting a surface of molten metal by the molten metal level sensor.
    Type: Grant
    Filed: August 9, 1999
    Date of Patent: January 8, 2002
    Assignee: Nippon Steel Corporation
    Inventors: Keisuke Fujisaki, Kiyoshi Wajima, Hideki Matsuda, Masahiro Tani
  • Patent number: 6336496
    Abstract: An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefore, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: January 8, 2002
    Assignees: Nippon Steel Corporation, Shingeo Asai
    Inventors: Shigeo Asai, Takehiko Toh, Kiyoshi Wajima, Kenzo Sawada, Eiichi Takeuchi, Kensuke Sassa, Tingju Li
  • Patent number: 5746268
    Abstract: A method and an apparatus for continuously casting a metal slab made of steel are provided for uniformly circulating molten metal on a meniscus in a mold. The cast metal slab has no surface defect such as a slitting. On the meniscus, the method and apparatus operates to generate electromagnetic stirring thrusts along two long mold sides, these thrusts being opposed to each other. The thrust oriented from a dipping nozzle to the short mold side is made larger than the thrust oriented from the short mold side to the dipping nozzle. A circuit for connecting each coil of a shifting field electromagnetic stirring coil part with a three-phase power supply is symmetric to another circuit with respect to the dipping nozzle. The circuit is divided into two parts along each long mold side. The divided circuit parts are located in parallel but have respective impedances.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: May 5, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Keisuke Fujisaki, Kiyoshi Wajima, Kenji Umetsu, Kenzo Sawada, Takatsugu Ueyama, Takehiko Toh, Kensuke Okazawa, Yasushi Okumura
  • Patent number: 5722480
    Abstract: An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefor, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: March 3, 1998
    Assignees: Nippon Steel Corporation, Shigeo Asai
    Inventors: Shigeo Asai, Takehiko Toh, Kiyoshi Wajima, Kenzo Sawada, Eiichi Takeuchi, Kensuke Sassa, Tingju Li