Patents by Inventor Isao Takagawa

Isao Takagawa 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: 9328683
    Abstract: An object is to provide an electronically controlled diesel engine capable of inhibiting the drastic increase of the fuel injection quantity from the fuel injection quantity before acceleration without the measurement of the relation between the number of revolutions of an engine, boost pressure, and the upper smoke limit of the fuel injection quantity. An electronically controlled diesel engine includes an judge part of an acceleration (64) that judges whether a control of acceleration is finished or not based on a difference between a target number of revolutions of the engine (Nset) and an actual number of revolutions of the engine (Ne).
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: May 3, 2016
    Assignee: Yanmar Co., Ltd.
    Inventors: Isao Takagawa, Hitoshi Adachi, Go Asai, Kazuhiro Yamada, Tomohiro Fukuda, Takashi Miyamoto
  • Patent number: 8712671
    Abstract: Provided is an engine rpm control device which gradually reduces the output speed of an engine drive object when reducing the engine rpm. The engine rpm control device (20) includes a target engine rpm correction means used upon detection of an engine failure. The target engine rpm correction means has a storage device (51) containing a map of the correlation characteristic between the engine rpm and the output speed of object to be driven by an engine (100). The target engine rpm correction means corrects the target engine rpm so that an instructed engine rpm (Nset) or a derating target engine rpm (Nset?) is shifted to a predetermined failure-preventing engine rpm (N2) while maintaining the reduction ratio of the output speed of the drive object at a predetermined ratio.
    Type: Grant
    Filed: October 7, 2009
    Date of Patent: April 29, 2014
    Assignee: Yanmar Co., Ltd.
    Inventors: Hitoshi Adachi, Takeshi Takahashi, Isao Takagawa
  • Patent number: 8176895
    Abstract: In an electronic control governor that adjusts the amount of fuel supplied to an engine so as to coincide an engine rotation speed with a target rotation speed, by driving an actuator for actuating a fuel adjusting mean due to an actuator driving current overlapped with a dither current, an amplitude or frequency of the dither current is changed, corresponding to a change in the supply quantity of the actuator driving current. Or, the amplitude and frequency of the dither current are changed corresponding to a change in the engine rotation speed. Alternatively, a ratio between turn-on time and turn-off time during one period of the dither current is changed, depending on the velocity ratio between the increased velocity and the decreased velocity of the actuator driving current. Preferably, the ratio of the turn-on time to one period of the dither current is set at 20 to 40%.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: May 15, 2012
    Assignee: Yanmar Co., Ltd.
    Inventors: Hokuto Kusaka, Hideo Shiomi, Isao Takagawa
  • Patent number: 8096286
    Abstract: A method for controlling an internal combustion engine, in which a traveling with reduced cylinders is controlled according to the idle-speed after the engine starting, so as to restrain the discharge of white smokes at the time lag for temperature equilibration soon after a cold starting. The method comprises a coolant water temperature detecting means 10 for detecting the coolant water temperature in the internal combustion engine 1, a rotation speed detecting means 12 for detecting the rotation speed of the internal combustion engine 1 and a control means for controlling the operation of the internal combustion engine 1 in accordance with the coolant water temperature and the rotation speed. When the internal combustion engine is evaluated that it is at the cold starting and the rotation speed reaches the predetermined rotation speed after the engine starting, a traveling with reduces cylinders is performed, which reduces the number of cylinders injecting fuels for a certain period of time.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: January 17, 2012
    Assignee: Yanmar Co., Ltd.
    Inventors: Gou Asai, Hitoshi Adachi, Isao Takagawa, Takashi Miyamoto
  • Publication number: 20110320105
    Abstract: An object is to provide an electronically controlled diesel engine capable of inhibiting the drastic increase of the fuel injection quantity from the fuel injection quantity before acceleration without the measurement of the relation between the number of revolutions of an engine, boost pressure, and the upper smoke limit of the fuel injection quantity. An electronically controlled diesel engine includes an judge part of an acceleration (64) that judges whether a control of acceleration is finished or not based on a difference between a target number of revolutions of the engine (Nset) and an actual number of revolutions of the engine (Ne).
    Type: Application
    Filed: September 16, 2009
    Publication date: December 29, 2011
    Applicant: Yanmar Co., Ltd.
    Inventors: Isao Takagawa, Hitoshi Adachi, Go Asai, Kazuhiro Yamada, Tomohiro Fukuda, Takashi Miyamoto
  • Publication number: 20110202261
    Abstract: Provided is an engine rpm control device which gradually reduces the output speed of an engine drive object when reducing the engine rpm. The engine rpm control device (20) includes a target engine rpm correction means used upon detection of an engine failure. The target engine rpm correction means has a storage device (51) containing a map of the correlation characteristic between the engine rpm and the output speed of object to be driven by an engine (100). The target engine rpm correction means corrects the target engine rpm so that an instructed engine rpm (Nset) or a derating target engine. rpm (Nset?) is shifted to a predetermined failure-preventing engine rpm (N2) while maintaining the reduction ratio of the output speed of the drive object at a predetermined ratio.
    Type: Application
    Filed: October 7, 2009
    Publication date: August 18, 2011
    Inventors: Hitoshi Adachi, Takeshi Takahashi, Isao Takagawa
  • Publication number: 20100108030
    Abstract: In an electronic control governor (1) that adjusts amount of fuel supplied to an engine so as to coincide an engine rotation speed with an target rotation speed, by driving an actuator (2) for actuating a fuel adjusting mean, due to an actuator driving current overlapped with a dither current, an amplitude or frequency of the dither current is changed, corresponding to change in supply quantity of the actuator driving current. Or, the amplitude and frequency of the dither current are changed, corresponding to change in the engine rotation speed. Alternatively, a ratio between turn-on time and turn-off time during one period of the dither current is changed, depending on velocity ratio between increased velocity and decreased velocity of the actuator driving current. Preferably, the ratio of the turn-on time to one period of the dither current is set at 20 to 40%.
    Type: Application
    Filed: February 26, 2008
    Publication date: May 6, 2010
    Applicant: Yanmar Co., Ltd.
    Inventors: Hokuto Kusaka, Hideo Shiomi, Isao Takagawa
  • Publication number: 20100063710
    Abstract: A method for controlling an internal combustion engine, in which a traveling with reduced cylinders is controlled according to the idle-speed after the engine starting, so as to restrain the discharge of white smokes at the time lag for temperature equilibration soon after a cold starting. The method comprises a coolant water temperature detecting means 10 for detecting the coolant water temperature in the internal combustion engine 1, a rotation speed detecting means 12 for detecting the rotation speed of the internal combustion engine 1 and a control means for controlling the operation of the internal combustion engine 1 in accordance with the coolant water temperature and the rotation speed. When the internal combustion engine is evaluated that it is at the cold starting and the rotation speed reaches the predetermined rotation speed after the engine starting, a traveling with reduces cylinders is performed, which reduces the number of cylinders injecting fuels for a certain period of time.
    Type: Application
    Filed: September 21, 2007
    Publication date: March 11, 2010
    Inventors: Gou Asai, Hitoshi Adachi, Isao Takagawa, Takashi Miyamoto