Patents by Inventor Hirokazu Nagura

Hirokazu Nagura 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: 8742704
    Abstract: The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: June 3, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Norihisa Iwasaki, Hirokazu Nagura
  • Publication number: 20120007528
    Abstract: The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.
    Type: Application
    Filed: February 26, 2010
    Publication date: January 12, 2012
    Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Norihisa Iwasaki, Hirokazu Nagura
  • Patent number: 7888893
    Abstract: The start timing of the pole position inference process of the linear motor installed vertically is delayed by a predetermined time after instruction of brake release. For example, from (1) increasing of the thrust instruction value of an ASR control system up to a predetermined value, (2) the movement (falling) distance of the moving part, or (3) the moving (falling) speed of the moving part, the release condition of the brake is detected and moreover after a predetermined time, the inference process of the pole position is started. The inference process of the pole position of a synchronous motor is fit to the release timing of a brake and a malfunction of the inference process and a runaway (falling in the vertical drive) of a moving part are prevented.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: February 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hirokazu Nagura, Hiromi Inaba, Toshifumi Yoshikawa, Hironori Ohashi, Yuri Takano, Masaki Sugiura
  • Publication number: 20100181945
    Abstract: The start timing of the pole position inference process of the linear motor installed vertically is delayed by a predetermined time after instruction of brake release. For example, from (1) increasing of the thrust instruction value of an ASR control system up to a predetermined value, (2) the movement (falling) distance of the moving part, or (3) the moving (falling) speed of the moving part, the release condition of the brake is detected and moreover after a predetermined time, the inference process of the pole position is started. The inference process of the pole position of a synchronous motor is fit to the release timing of a brake and a malfunction of the inference process and a runaway (falling in the vertical drive) of a moving part are prevented.
    Type: Application
    Filed: March 2, 2010
    Publication date: July 22, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Hirokazu Nagura, Hiromi Inaba, Toshifumi Yoshikawa, Hironori Ohashi, Yuri Takano, Masaki Sugiura
  • Patent number: 7104363
    Abstract: An elevator having a power feeding apparatus effective for reducing the installation space for the elevator is disclosed. The dimension of the power transmission part disposed at the hoist way and the dimension of the power receiving part mounted on the counter weight, each measured in the direction along which the counter weight moves are made different from each other.
    Type: Grant
    Filed: October 5, 2001
    Date of Patent: September 12, 2006
    Inventors: Kazuhisa Mori, Kouki Yamamoto, Hideki Ayano, Ikuo Yamato, Hiromi Inaba, Hirokazu Nagura, Hideki Nihei
  • Publication number: 20060043921
    Abstract: The start timing of the pole position inference process of the linear motor installed vertically is delayed by a predetermined time after instruction of brake release. For example, from (1) increasing of the thrust instruction value of an ASR control system up to a predetermined value, (2) the movement (falling) distance of the moving part, or (3) the moving (falling) speed of the moving part, the release condition of the brake is detected and moreover after a predetermined time, the inference process of the pole position is started. The inference process of the pole position of a synchronous motor is fit to the release timing of a brake and a malfunction of the inference process and a runaway (falling in the vertical drive) of a moving part are prevented.
    Type: Application
    Filed: August 29, 2005
    Publication date: March 2, 2006
    Inventors: Hirokazu Nagura, Hiromi Inaba, Toshifumi Yoshikawa, Hironori Ohashi, Yuri Takano, Masaki Sugiura
  • Patent number: 6481531
    Abstract: The number of electrical wires in the car is reduced by radio communications between the operation panel and terminal. Furthermore, reliability and dependability of communications are improved because the operation panel and terminal communicate with each other at a comparatively short distance.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: November 19, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hirokazu Nagura, Hiromi Inaba, Sadao Hokari, Atsuya Fujino
  • Publication number: 20020157903
    Abstract: The number of electrical wires in the car is reduced by radio communications between the operation panel and terminal. Furthermore, reliability and dependability of communications are improved because the operation panel and terminal communicate with each other at a comparatively short distance.
    Type: Application
    Filed: September 20, 2001
    Publication date: October 31, 2002
    Applicant: HITACHI, LTD.
    Inventors: Hirokazu Nagura, Hiromi Inaba, Sadao Hokari, Atsuya Fujino
  • Publication number: 20020112924
    Abstract: An elevator having a power feeding apparatus effective for reducing the installation space for the elevator is disclosed.
    Type: Application
    Filed: October 5, 2001
    Publication date: August 22, 2002
    Applicant: Hitachi Ltd.
    Inventors: Kazuhisa Mori, Kouki Yamamoto, Hideki Ayano, Ikuo Yamato, Hiromi Inaba, Hirokazu Nagura, Hideki Nihei