Patents by Inventor Yusuke Kajita

Yusuke Kajita 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: 20240097044
    Abstract: According to one embodiment, a semiconductor device includes a first conductive layer between first and second insulating layers with an oxide semiconductor column extending in the first direction through these layers. A third insulating layer covers the column. The column has a first semiconductor portion at a first position matching the first insulating layer, a second semiconductor portion at a second position matching second insulating layer, and a third semiconductor portion at a third position matching the first conductive layer. The first semiconductor portion is continuous along a second direction between the third insulating layer, the second semiconductor portion is continuous along the second direction between the third insulating layer, but the third semiconductor portion is not continuous between the third insulating layer.
    Type: Application
    Filed: August 25, 2023
    Publication date: March 21, 2024
    Inventors: Yusuke KASAHARA, Kappei IMAMURA, Akifumi GAWASE, Shinji MORI, Akihiro KAJITA
  • Patent number: 9617715
    Abstract: A construction machine including an internal combustion engine controlled based on a torque command, an electric motor mechanically connected to the internal combustion engine, and an electric energy storage device that supplies electric power to the electric motor, the construction machine performing work by driving a hydraulic pressure generator using the internal combustion engine and the electric motor, the construction machine including: a speed control device that controls a speed of the electric motor based on a speed command; and a torque limiter that limits the torque command relative to a torque target, wherein the torque command is limited by the torque limiter in such a manner that a rate of change with time of the torque command is limited to be equal to or less than a predetermined value.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: April 11, 2017
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji Ishida, Hidetoshi Satake, Yusuke Kajita, Shiro Yamaoka
  • Patent number: 9421873
    Abstract: Construction machine capable of incorporating an engine and using an external power source. The construction machine includes an electrical storage device performing a charge with the external power source, uses the electrical storage device to provide assist when the power of the engine is insufficient, uses an electrical charge in the electrical storage device systematically in accordance with work time, and efficiently uses the electrical storage device by controlling its discharge amount in accordance with load status. The construction machine includes the engine, accessory loads connected to the engine, an assist electric motor driven by the engine, electrical power converters for converting an AC current, which is the output current of the assist electric motor, to a DC current, and the electrical storage device connected to the DC side of each electrical power converter. The electrical storage device becomes charged through a charging device from the external power source.
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: August 23, 2016
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Seiji Ishida, Masataka Sasaki, Yusuke Kajita, Hidetoshi Satake, Takako Satake, Manabu Edamura, Kazuo Fujishima, Shiho Izumi
  • Patent number: 9399856
    Abstract: A hydraulic working machine has an assist electric motor connected to an engine and a hydraulic pump. The emissions of air pollutants in the exhaust gas from the engine are minimized regardless of fluctuations in the load torque of the hydraulic pump. A specific revolution speed suitable for reducing the emissions of air pollutants is stored, and an engine is controlled using the specific revolution speed as a target revolution speed. The absorption torque of a hydraulic pump is subjected to high-pass filtering whereby a high-frequency component devoid of a trend component is obtained. Target assist torque is computed from the high-frequency component, and the assist electric motor is subjected to power running/generation control accordingly. A specific output torque range suitable for reducing the emissions of air pollutants is stored, and the target assist torque is corrected so that the trend component does not exceed the specific output torque range.
    Type: Grant
    Filed: May 24, 2012
    Date of Patent: July 26, 2016
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Kazuo Fujishima, Yusuke Kajita, Mitsuo Sonoda, Masatoshi Hoshino, Akira Nakayama, Junji Yamamoto, He Bao, Seiji Ishida, Shiro Yamaoka, Takashi Okada
  • Publication number: 20160153176
    Abstract: A construction machine including an internal combustion engine controlled based on a torque command, an electric motor mechanically connected to the internal combustion engine, and an electric energy storage device that supplies electric power to the electric motor, the construction machine performing work by driving a hydraulic pressure generator using the internal combustion engine and the electric motor, the construction machine including: a speed control device that controls a speed of the electric motor based on a speed command; and a torque limiter that limits the torque command relative to a torque target, wherein the torque command is limited by the torque limiter in such a manner that a rate of change with time of the torque command is limited to be equal to or less than a predetermined value.
    Type: Application
    Filed: February 4, 2016
    Publication date: June 2, 2016
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji ISHIDA, Hidetoshi SATAKE, Yusuke KAJITA, Shiro YAMAOKA
  • Patent number: 9341198
    Abstract: A hydraulic drive device for a hydraulic excavator, includes: a first hydraulic pump; a first boom directional control valve and a second arm directional control valve which are connected in parallel to the first pump; a second hydraulic pump; and a second boom directional control valve and a first arm directional control valve which are connected in parallel to the second pump; wherein: the hydraulic drive device also includes: a third hydraulic pump; a third boom directional control valve connected to the third pump and controlling the flow of pressure oil supplied to a boom cylinder; and a third arm directional control valve connected in tandem with the third boom directional control valve and controlling the flow of pressure oil supplied to an arm cylinder.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: May 17, 2016
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsuyoshi Nakamura, Kazunori Nakamura, Yasuo Okano, Kouji Ishikawa, Kensuke Sato, Hiroyuki Azuma, Mitsuhiko Kanehama, Yusuke Kajita
  • Patent number: 9249879
    Abstract: A hydraulic drive system designed so that while maintaining intact a structure of a relief valve having a shockless function, the drive unit hydraulic drive system facilitates changing a driving pressure or braking pressure of a hydraulic swing motor and hence, changing a maximum driving torque or braking torque of the hydraulic swing motor. Inside a swing motor unit is arranged a first swinging relief valve provided with a shockless function to limit a driving pressure or braking pressure of the hydraulic swing motor in order to prevent the pressure from exceeding a first setting pressure. Also, a second swinging relief valve is provided for limiting the driving pressure or braking pressure of the hydraulic swing motor in order to prevent the pressure from exceeding a second setting pressure that is lower than the first setting pressure.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: February 2, 2016
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Kouji Ishikawa, Yusuke Kajita, Hidetoshi Satake, Takatoshi Ooki
  • Patent number: 9020707
    Abstract: Disclosed is a hybrid-type construction machine equipped with a swing hydraulic motor 27 and a swing electric motor 25 in combination to save energy, the construction machine ensuring high operability of a swing body 20 and providing high energy efficiency. In accordance with the amount of manipulation of a swing control lever 72, the construction machine changes a rate of a torque of the swing electric motor 25 with respect to that of the swing hydraulic motor 27. The construction machine also controls a relief pressure and the torque of the swing electric motor 25 in accordance with the amount of manipulation of a swing control lever 72, a pressure of the swing hydraulic motor 27, and a rotating speed of the swing electric motor 25.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: April 28, 2015
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinya Imura, Seiji Ishida, Kouji Ishikawa, Yusuke Kajita, Hidetoshi Satake, Takatoshi Ooki, Manabu Edamura
  • Patent number: 8950180
    Abstract: A hybrid construction machine drives the upper swing structure using a hydraulic motor and an electric motor together and is capable of regenerating the energy of the upper swing structure in deceleration or stopping into electric power and using the regenerated electric power for assisting the hydraulic motor for driving the upper swing structure. The opening area characteristics of a meter-out restrictor and a bleed-off restrictor of a swing directional control valve are set to become larger than for construction machines driving the upper swing structure with the hydraulic motor alone. Torque of the electric motor is controlled so that the total sum of the actual torque occurring in the hydraulic and electric motors in deceleration or acceleration of the hydraulic motor equals the torque occurring when the opening area of the meter-out restrictor or the bleed-off restrictor is set at the prescribed opening area.
    Type: Grant
    Filed: March 22, 2012
    Date of Patent: February 10, 2015
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takatoshi Ooki, Yusuke Kajita, Hidetoshi Satake, Seiji Ishida, Shiho Izumi, Kouji Ishikawa, Shinya Okumura, Manabu Edamura
  • Patent number: 8924100
    Abstract: A hybrid construction machine is provided with a variable displacement hydraulic pump 1 which supplies hydraulic oil to a hydraulic actuator, an engine 2 which is provided to be able to drive and rotate the hydraulic pump 1, an electric motor 3 which is provided to be able to drive and rotate the hydraulic pump 1, an engine control dial 4, a controller 4 and an operating lever 5. The controller changes the rotation speed of the engine 2 to reduce fuel consumption according to power generated by the engine 2, and changes displacement of the hydraulic pump 1 based on the rotation speed of the engine 2, the dial position of the engine control dial 4 and the amount of operation on the operating lever 5.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: December 30, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinya Imura, Seiji Ishida, Yusuke Kajita, Kazuo Fujishima, Takatoshi Ooki, Takako Satake
  • Publication number: 20140188321
    Abstract: An object of the present invention is to provide a construction machine that can reduce particulate matter (PM) or nitrogen oxide (NOx) discharged from an internal combustion engine mounted on the construction machine. The construction machine 200 includes a diesel engine 101 controlled based on a torque command, an electric motor 102 mechanically connected to the diesel engine, an electric energy storage device 111 that supplies electric power to the electric motor, and a hydraulic pump 103. The construction machine performs work by driving the hydraulic pump using the diesel engine and the electric motor. A speed control device 118 controls a speed of the electric motor 102 based on a speed command. A torque limiter 115 obtains the torque command having a rate of change with time limited based on a torque target.
    Type: Application
    Filed: August 10, 2012
    Publication date: July 3, 2014
    Inventors: Seiji Ishida, Hideloshi Satake, Yusuke Kajita, Shiro Yamaoka
  • Publication number: 20140147238
    Abstract: An object of the present invention is to provide a construction machine that is capable of effectively charging electrical power into the capacitor in consideration of the drive of a swing section and hydraulic work device. To achieve the object, the present invention grasps the status of the construction machine (2) in advance to calculate energy, predicts the next operation, determines the amount of energy to be charged into a capacitor (13), and controls a DC-DC converter (15) accordingly. Consequently, the loss in a conventional battery (lead storage battery) during regeneration can be reduced to provide increased efficiency.
    Type: Application
    Filed: October 4, 2011
    Publication date: May 29, 2014
    Inventors: Masataka Sasaki, Manabu Edamura, Yusuke Kajita, Seiji Ishida, Shiho Izumi, Takako Satake, Kazuo Fujishima
  • Publication number: 20140103874
    Abstract: Construction machine capable of incorporating an engine and using an external power source. The construction machine includes an electrical storage device performing a charge with the external power source, uses the electrical storage device to provide assist when the power of the engine is insufficient, uses an electrical charge in the electrical storage device systematically in accordance with work time, and efficiently uses the electrical storage device by controlling its discharge amount in accordance with load status. The construction machine includes the engine, accessory loads connected to the engine, an assist electric motor driven by the engine, electrical power converters for converting an AC current, which is the output current of the assist electric motor, to a DC current, and the electrical storage device connected to the DC side of each electrical power converter. The electrical storage device becomes charged through a charging device from the external power source.
    Type: Application
    Filed: October 12, 2011
    Publication date: April 17, 2014
    Inventors: Shiho Izumi, Manabu Edamura, Takako Satake, Yusuke Kajita, Masataka Sasaki, Seiji Ishida, Kazuo Fujishima
  • Publication number: 20140090369
    Abstract: A hydraulic drive device for a hydraulic excavator, includes: a first hydraulic pump; a first boom directional control valve and a second arm directional control valve which are connected in parallel to the first pump; a second hydraulic pump; and a second boom directional control valve and a first arm directional control valve which are connected in parallel to the second pump; wherein: the hydraulic drive device also includes: a third hydraulic pump; a third boom directional control valve connected to the third pump and controlling the flow of pressure oil supplied to a boom cylinder; and a third arm directional control valve connected in tandem with the third boom directional control valve and controlling the flow of pressure oil supplied to an arm cylinder.
    Type: Application
    Filed: May 17, 2012
    Publication date: April 3, 2014
    Applicant: Hitachi Contruction Machinery Co., Ltd.
    Inventors: Tsuyoshi Nakamura, Kazunori Nakamura, Yasuo Okano, Kouji Ishikawa, Kensuke Sato, Hiroyuki Azuma, Mitsuhiko Kanehama, Yusuke Kajita
  • Publication number: 20140020375
    Abstract: A hydraulic working machine has an assist electric motor connected to an engine and a hydraulic pump. The emissions of air pollutants in the exhaust gas from the engine are minimized regardless of fluctuations in the load torque of the hydraulic pump. A specific revolution speed suitable for reducing the emissions of air pollutants is stored, and an engine is controlled using the specific revolution speed as a target revolution speed. The absorption torque of a hydraulic pump is subjected to high-pass filtering whereby a high-frequency component devoid of a trend component is obtained. Target assist torque is computed from the high-frequency component, and the assist electric motor is subjected to power running/generation control accordingly. A specific output torque range suitable for reducing the emissions of air pollutants is stored, and the target assist torque is corrected so that the trend component does not exceed the specific output torque range.
    Type: Application
    Filed: May 24, 2012
    Publication date: January 23, 2014
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Kazuo Fujishima, Yusuke Kajita, Mitsuo Sonoda, Masatoshi Hoshino, Akira Nakayama, Junji Yamamoto, He Bao, Seiji Ishida, Shiro Yamaoka, Takashi Okada
  • Publication number: 20130197768
    Abstract: [Problem] To provide a hybrid construction machine which can provide the same operation feeling as an ordinary construction machine that is not hybrid without changing the discharge flow rate of a hydraulic pump even when the rotation speed of an engine is changed according to power absorbed by the hydraulic pump. [Solution] A hybrid construction machine is provided with a variable displacement hydraulic pump 1 which supplies hydraulic oil to a hydraulic actuator, an engine 2 which is provided to be able to drive and rotate the hydraulic pump 1, an electric motor 3 which is provided to be able to drive and rotate the hydraulic pump 1, an engine control dial 4, a controller 4 and an operating lever 5.
    Type: Application
    Filed: August 18, 2011
    Publication date: August 1, 2013
    Inventors: Shinya Imura, Seiji Ishida, Yusuke Kajita, Kazuo Fujishima, Takatoshi Ooki, Takako Satake
  • Publication number: 20130195597
    Abstract: Disclosed is a hybrid-type construction machine equipped with a swing hydraulic motor 27 and a swing electric motor 25 in combination to save energy, the construction machine ensuring high operability of a swing body 20 and providing high energy efficiency. In accordance with the amount of manipulation of a swing control lever 72, the construction machine changes a rate of a torque of the swing electric motor 25 with respect to that of the swing hydraulic motor 27. The construction machine also controls a relief pressure and the torque of the swing electric motor 25 in accordance with the amount of manipulation of a swing control lever 72, a pressure of the swing hydraulic motor 27, and a rotating speed of the swing electric motor 25.
    Type: Application
    Filed: October 5, 2011
    Publication date: August 1, 2013
    Inventors: Shinya Imura, Seiji Ishida, Kouji Ishikawa, Yusuke Kajita, Takatoshi Ooki, Manabu Edamura, Takako Satake
  • Publication number: 20130139678
    Abstract: A hydraulic drive system designed so that while maintaining intact a structure of a relief valve having a shockless function, the drive unit hydraulic drive system facilitates changing a driving pressure or braking pressure of a hydraulic swing motor and hence, changing a maximum driving torque or braking torque of the hydraulic swing motor. Inside a swing motor unit is arranged a first swinging relief valve provided with a shockless function to limit a driving pressure or braking pressure of the hydraulic swing motor in order to prevent the pressure from exceeding a first setting pressure. Also, a second swinging relief valve is provided for limiting the driving pressure or braking pressure of the hydraulic swing motor in order to prevent the pressure from exceeding a second setting pressure that is lower than the first setting pressure.
    Type: Application
    Filed: July 26, 2011
    Publication date: June 6, 2013
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Kouji Ishikawa, Yusuke Kajita, Hidetoshi Satake, Takatoshi Ooki
  • Patent number: 8336443
    Abstract: A hydraulic circuit for a hydraulic working machine is composed of a main pump 21, a boom cylinder 11 arranged for extension or contraction by pressure oil from the main pump 21, a directional control valve 22 for controlling flows of pressure oil to be fed from the main pump 21 to a bottom chamber 11a and rod chamber 12b of the boom cylinder 11, a control unit 23 for performing a change-over control of the directional control valve 22, a pilot pump 24, a jack-up selector valve 25 for controlling a flow of pressure oil delivered from the pilot pump 24, a flow control valve 26 connected on an upstream side of the directional control valve 22 to a meter-in port of the directional control valve 22 such that the flow control valve 26 can be changed over by the jack-up selector valve 25, and a center bypass selector valve 27 connected on a downstream side of the directional control valve 22 to a center bypass port of the directional control valve 22 such that the center bypass selector valve 27 can be changed over
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: December 25, 2012
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Toshihiro Abe, Yusuke Kajita, Kazunori Nakamura, Kouji Ishikawa, Hideo Karasawa
  • Publication number: 20120240581
    Abstract: A hybrid construction machine drives the upper swing structure using a hydraulic motor and an electric motor together and is capable of regenerating the energy of the upper swing structure in deceleration or stopping into electric power and using the regenerated electric power for assisting the hydraulic motor for driving the upper swing structure. The opening area characteristics of a meter-out restrictor and a bleed-off restrictor of a swing directional control valve are set to become larger than for construction machines driving the upper swing structure with the hydraulic motor alone. Torque of the electric motor is controlled so that the total sum of the actual torque occurring in the hydraulic and electric motors in deceleration or acceleration of the hydraulic motor equals the torque occurring when the opening area of the meter-out restrictor or the bleed-off restrictor is set at the prescribed opening area.
    Type: Application
    Filed: March 22, 2012
    Publication date: September 27, 2012
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Takatoshi OOKI, Yusuke KAJITA, Hidetoshi SATAKE, Seiji ISHIDA, Shiho IZUMI, Kouji ISHIKAWA, Shinya OKUMURA, Manabu EDAMURA