Patents by Inventor Fumio Yukawa

Fumio Yukawa 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).

  • Publication number: 20220052608
    Abstract: An object of the present invention is to provide a semiconductor oscillation suppression circuit capable of suppressing voltage oscillation of a switching element with low loss. A semiconductor oscillation suppression circuit includes a wide-bandgap semiconductor element and a capacitor connected to the wide-bandgap semiconductor element in parallel and having a larger capacity than a junction capacitance of the wide-bandgap semiconductor element.
    Type: Application
    Filed: October 27, 2021
    Publication date: February 17, 2022
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Fumio YUKAWA, Seiki IGARASHI
  • Publication number: 20040052913
    Abstract: The object of the present invention is to provide a process for maturing a food which makes possible to control the maturation degree of the food.
    Type: Application
    Filed: June 12, 2003
    Publication date: March 18, 2004
    Inventors: Yuichiro Uchida, Fumio Yukawa, Naoto Kobayashi
  • Patent number: 5623824
    Abstract: An air-fuel ratio control system for an automotive internal combustion engine provided with a three-way catalytic converter disposed in an exhaust gas passageway of the engine. The air-fuel ratio control system is comprised of an oxygen sensor disposed in the exhaust gas passageway downstream of the catalytic converter. The air-fuel ratio of air-fuel mixture to be supplied to the engine is controlled toward a stoichiometric value to cause the three-way catalytic converter to efficiently work under the action of a control unit including a microcomputer. In the control unit, a control constant is set in accordance with the output voltage of the oxygen sensor, and a cycle signal (pulse signal) is cyclically generated. The control constant is compulsorily minutely vibrated under the action of the cycle signal, thereby obtaining an air-fuel ratio correction coefficient.
    Type: Grant
    Filed: February 18, 1994
    Date of Patent: April 29, 1997
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Fumio Yukawa, Tsutomu Kikuchi
  • Patent number: 5050083
    Abstract: A system and method for controlling an air/fuel mixture for an internal combustion engine are disclosed in which an integration constant used for a calculation of an integration portion included in a feedback correction coefficient (.alpha.) of the air/fuel mixture ratio after a relationship between an actual air/fuel mixture raito and target (stoichiometric) air/fuel mixture ratio has been inverted is set and varied according to an engine driving condition, so that the integration constant meets requirements of a stability during an engine steady driving condition and a favorable responsive characteristic during an engine transient condition. In a preferred embodiement, a fuzzy control is applicable to the calculation of the integration constant.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: September 17, 1991
    Assignee: Nissan Motor Company, Limited
    Inventors: Masaaki Uchida, Hideki Uema, Fumio Yukawa, Kunifumi Sawamoto, Toyaki Nakagawa, Naoki Nakada
  • Patent number: 4786476
    Abstract: The invention relates to a gas sensor element which utilizes a change in the electric resistance of a porously fired TiO.sub.2 layer. To improve the speed of response of the gas sensor element, and also to strengthen the adhesion of the fired TiO.sub.2 layer to a ceramic substrate, at least one kind of metal oxide which hardly undergoes solid phase reaction with TiO.sub.2 and serves as a sintering suppressing agent, such as Er.sub.2 O.sub.3, Sm.sub.2 O.sub.3 and/or In.sub.2 O.sub.3, is added to TiO.sub.2 in advance of firing. The speed of response is further enhanced by the addition of at least one kind of noble metal such as Pt and/or Rh to TiO.sub.2 together with the sintering suppressing oxide(s).
    Type: Grant
    Filed: July 16, 1986
    Date of Patent: November 22, 1988
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Fumio Munakata, Masayuki Touda, Masaaki Uchida, Fumio Yukawa
  • Patent number: 4772376
    Abstract: An air/fuel ratio sensor has an oxygen sensor cell including a primary measuring element in direct contact with a gas such as exhaust gases of an automotive engine, and an oxygen pump cell formed by inner and outer electrodes and a cover of an oxygen ion conductive solid electrolyte which confines the primary measuring element within a gas diffusion control space, and which has a small gas diffusion hole. The primary measuring element is formed with a central opening whose center lies right below the gas diffusion hole, in order to reduce a burden imposed on the oxygen pump cell and prevent overshoot in a sensor response characteristic.
    Type: Grant
    Filed: March 9, 1987
    Date of Patent: September 20, 1988
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Fumio Yukawa, Masayuki Touda, Shinji Kimura, Fumio Munakata, Satoru Ichikawa