Patents by Inventor Kazuo Fujishima

Kazuo Fujishima 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: 9863124
    Abstract: To provide construction machinery capable of more efficiently utilizing the energy of return hydraulic oil from a hydraulic actuator.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: January 9, 2018
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji Ishihara, Masatoshi Hoshino, Kazuo Fujishima
  • Patent number: 9816252
    Abstract: This invention is a hydraulic work machine having an electric assist motor coupled to an engine and a hydraulic pump, in the hydraulic work machine of which, a rotational speed and torque of the engine are controlled so that an operating point of the engine moves along a predetermined route for yielding a combustion state of the engine under a transient state that the engine changes in speed and torque. A target speed and torque of the engine 7 are set so that the rotational speed and torque of the engine 7 will change along a predetermined route F in a running region of the engine, respective rates of change of the target rotational speed and torque of the engine 7 are limited, and the engine 7 is controlled to yield the target engine speed. In addition, torque of the assist motor 10 is controlled to yield the target torque of the engine.
    Type: Grant
    Filed: May 10, 2013
    Date of Patent: November 14, 2017
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masatoshi Hoshino, Shinji Ishihara, Kazuo Fujishima
  • Publication number: 20160289923
    Abstract: To provide construction machinery capable of more efficiently utilizing the energy of return hydraulic oil from a hydraulic actuator.
    Type: Application
    Filed: May 20, 2014
    Publication date: October 6, 2016
    Inventors: Shinji ISHIHARA, Masatoshi HOSHINO, Kazuo FUJISHIMA
  • 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
  • Patent number: 9284718
    Abstract: A power regeneration device for an operating machine has a hydraulic cylinder and a return line through which fluid returning to a tank flows when the hydraulic cylinder contracts. The return line branches into a plurality of hydraulic lines through a branching part and includes a regeneration line that which leads returning fluid to the tank via a hydraulic motor to which a generator is connected. A control valve line is connected to the branching part and leads the returning fluid to the tank via a control valve. An electricity storage device stores electric power generated by the generator, and an electric amount detector detects the electric amount of the electricity storage device. A flow rate calculator calculates the flow rate of the returning fluid flowing through the regeneration line and the flow rate of the returning fluid flowing through the control valve line depending on an electric amount signal.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: March 15, 2016
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Seiji Hijikata, Kazuo Fujishima
  • Patent number: 9212469
    Abstract: There is provided a hydraulic excavator including a hydraulic pump (6) driven by an engine (7), a boom cylinder (3a) driven by hydraulic fluid delivered from the hydraulic pump (6), a swing motor (16) driven electrically, an operating device (4A) for operating the boom cylinder (3a), an operating device (4B) for operating the swing motor (16), and a vehicle body controller (11) which limits the power of the swing motor (16) in accordance with the operation amount of the operating device (4A) when the two operating devices (4A, 4B) are operated in combination. The power limit value of the swing motor (16) varies depending on the output of the engine (7). This allows a good operational feeling to be retained in combined operation regardless of the operating state of the engine.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: December 15, 2015
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Tsutomu Udagawa, Kazuo Fujishima, Koji Ishikawa, Hidetoshi Satake, Yuichi Kunitomo
  • Publication number: 20150225927
    Abstract: This invention is a hydraulic work machine having an electric assist motor coupled to an engine and a hydraulic pump, in the hydraulic work machine of which, a rotational speed and torque of the engine are controlled so that an operating point of the engine moves along a predetermined route for yielding a combustion state of the engine under a transient state that the engine changes in speed and torque. A target speed and torque of the engine 7 are set so that the rotational speed and torque of the engine 7 will change along a predetermined route F in a running region of the engine, respective rates of change of the target rotational speed and torque of the engine 7 are limited, and the engine 7 is controlled to yield the target engine speed. In addition, torque of the assist motor 10 is controlled to yield the target torque of the engine.
    Type: Application
    Filed: May 10, 2013
    Publication date: August 13, 2015
    Inventors: Masatoshi Hoshino, Shinji Ishihara, Kazuo Fujishima
  • Patent number: 8938338
    Abstract: To provide a system for controlling a construction machine, which can be implemented inexpensively, can detect a failure in any of pressure sensors, controllers, an inverter device, and an electric motor for swing, and can secure safety and required workability for an operator. Redundant hydraulic pressure sensors 20, 21 provide input to a first controller 11 for calculating a swing command, and a second controller 22 provided in an inverter device 13 for controlling an electric motor 16 for swing. The second controller 2 detects an abnormality in any of the hydraulic pressure sensors 20, 21 and the first controller 11 by a process for determining the validity of a swing command signal, and allows the swing operation to continue by using a signal from the second hydraulic pressure sensor 21 when determination is made based on the contents of the abnormality that the electric motor 16 for swing can operate normally.
    Type: Grant
    Filed: February 16, 2012
    Date of Patent: January 20, 2015
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kohei Sakurai, Kotaro Shimamura, Kazuo Fujishima
  • 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: 20140371995
    Abstract: There is provided a hydraulic excavator including a hydraulic pump (6) driven by an engine (7), a boom cylinder (3a) driven by hydraulic fluid delivered from the hydraulic pump (6), a swing motor (16) driven electrically, an operating device (4A) for operating the boom cylinder (3a), an operating device (4B) for operating the swing motor (16), and a vehicle body controller (11) which limits the power of the swing motor (16) in accordance with the operation amount of the operating device (4A) when the two operating devices (4A, 4B) are operated in combination. The power limit value of the swing motor (16) varies depending on the output of the engine (7). This allows a good operational feeling to be retained in combined operation regardless of the operating state of the engine.
    Type: Application
    Filed: December 18, 2012
    Publication date: December 18, 2014
    Inventors: Tsutomu Udagawa, Kazuo Fujishima, Koji Ishikawa, Hidetoshi Satake, Yuichi Kunitomo
  • Patent number: 8874327
    Abstract: Target rotation speed setup section for setting a target engine rotation speed; load detection for detecting a hydraulic pump load; an assist output computation section for calculating an assist output to be generated by a motor generator in accordance with a rotation speed deviation ?N, which is the difference between an actual and target rotation speed, or in accordance with the hydraulic pump load; an absorption torque upper limit computation section for calculating an absorption torque upper limit value of the hydraulic pump; and an operation signal generation section for generating the operation signal to be output to a pump displacement adjustment device. When the rotation speed deviation ?N is equal to or more than a setting NC determined in accordance with the assist output value, the absorption torque upper limit computation section reduces the absorption torque upper limit value of the hydraulic pump from the calculated value.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: October 28, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji Ishihara, Shinya Imura, Masatoshi Hoshino, Kazuo Fujishima
  • Publication number: 20140283508
    Abstract: A drive system suppresses cylinder speed fluctuation at times of load inversion in a hydraulic closed circuit system in which a single rod cylinder is driven by a hydraulic pump. The drive system has a control device including: pressure detection means which detect pressure in a rod-side hydraulic chamber of the hydraulic cylinder and pressure in a head-side hydraulic chamber of the hydraulic cylinder; load calculation means which calculates the load on the hydraulic cylinder from the pressure in the rod-side hydraulic chamber and the pressure in the head-side hydraulic chamber; load switching means which calculates a first proportional gain in accordance with the polarity of the calculated load; and multiplication means which calculates a command signal by multiplying the calculated first proportional gain and an operation amount input from the operating device together and outputs the calculated command signal to the delivery flow rate control means.
    Type: Application
    Filed: December 3, 2012
    Publication date: September 25, 2014
    Inventors: Kenji Hiraku, Kazuo Fujishima
  • 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: 20140090367
    Abstract: A power regeneration device for an operating machine has a hydraulic cylinder and a return line through which fluid returning to a tank flows when the hydraulic cylinder contracts. The return line branches into a plurality of hydraulic lines through a branching part and includes a regeneration line that which leads returning fluid to the tank via a hydraulic motor to which a generator is connected. A control valve line is connected to the branching part and leads the returning fluid to the tank via a control valve. An electricity storage device stores electric power generated by the generator, and an electric amount detector detects the electric amount of the electricity storage device. A flow rate calculator calculates the flow rate of the returning fluid flowing through the regeneration line and the flow rate of the returning fluid flowing through the control valve line depending on an electric amount signal.
    Type: Application
    Filed: June 13, 2012
    Publication date: April 3, 2014
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Seiji Hijikata, Kazuo Fujishima
  • Patent number: 8659177
    Abstract: A motive power regeneration apparatus for a working machine includes a regeneration circuit that is connected to a hydraulic line through which a returning fluid of a boom cylinder is distributed during a boom lowering operation. Also included are a hydraulic motor connected to a generator, a flow regulating circuit that is connected to the hydraulic line and provided with a control valve, an inverter that controls the flow rate on the regeneration circuit in accordance with a first flow rate setting which varies with the operation amount of an operating apparatus, and a control valve and a proportional valve that control the flow rate on the flow regulating circuit in accordance with a second flow rate setting which varies with the operation amount of the operating apparatus. Therefore, the motive power regeneration apparatus is capable of making an operator constantly feel comfortable with the working machine operations.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: February 25, 2014
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuo Fujishima, Mitsuo Sonoda, Seiji Hijikata
  • 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: 20130325268
    Abstract: The present invention includes a target rotation speed setup section (17) for setting a target rotation speed of an engine (1); load detection means (21) for detecting a load on a hydraulic pump (3); an assist output computation section (19) for calculating an assist output to be generated by a motor generator in accordance with a rotation speed deviation ?N, which is the difference between an actual rotation speed and the target rotation speed, or in accordance with the load on the hydraulic pump; an absorption torque upper limit computation section (23) for calculating an absorption torque upper limit value of the hydraulic pump (3); and an operation signal generation section (24) for generating the operation signal to be output to a pump displacement adjustment device (45).
    Type: Application
    Filed: January 5, 2012
    Publication date: December 5, 2013
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Shinji Ishihara, Shinya Imura, Masatoshi Hoshino, Kazuo Fujishima
  • Publication number: 20130317710
    Abstract: To provide a system for controlling a construction machine, which can be implemented inexpensively, can detect a failure in any of pressure sensors, controllers, an inverter device, and an electric motor for swing, and can secure safety and required workability for an operator. Redundant hydraulic pressure sensors 20, 21 provide input to a first controller 11 for calculating a swing command, and a second controller 22 provided in an inverter device 13 for controlling an electric motor 16 for swing. The second controller 2 detects an abnormality in any of the hydraulic pressure sensors 20, 21 and the first controller 11 by a process for determining the validity of a swing command signal, and allows the swing operation to continue by using a signal from the second hydraulic pressure sensor 21 when determination is made based on the contents of the abnormality that the electric motor 16 for swing can operate normally.
    Type: Application
    Filed: February 16, 2012
    Publication date: November 28, 2013
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Kohei Sakurai, Kotaro Shimamura, Kazuo Fujishima