Patents by Inventor Masafumi HITA

Masafumi HITA 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: 10458097
    Abstract: A hybrid work machine that can suppress excessive limiting on pump absorption power even in a situation in which supply of electric power to an electric motor is limited is provided. The hybrid work machine includes: an engine 22; an assist generator motor 23 connected to the engine 22 in such a manner that a torque can be transmitted to the engine 22; an electric storage device 24 that supplies electric power to the assist generator motor 23; a monitoring device 28 that monitors the electric storage device 24 and that acquires electric storage device information; a hydraulic pump 41 driven by the engine 22 and the assist generator motor 23; and a pump regulator 43 that regulates a delivery flow rate of the hydraulic pump 41.
    Type: Grant
    Filed: September 2, 2016
    Date of Patent: October 29, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hiroaki Amano, Shinya Imura, Ryouhei Yamashita, Shinji Ishihara, Shinji Nishikawa, Masafumi Hita
  • Patent number: 10435863
    Abstract: A control system for a construction machine maintains operability of a swing combined operation even when the power supplied from an engine or storage device varies. The control system includes a target path computation section that receives an operation amount of the front implement operation device, an operation amount of the swing operation device, a speed of the front implement drive unit detected, and an angular speed of the swing structure drive unit, and that computes a target path of a claw tip position of the front implement drive unit; and an actuator power computation section that regulates power supplied to the front implement drive unit or the swing structure drive unit in such a manner that a claw tip of the front implement drive unit follows the target path the front implement operation device and the swing operation device are operated simultaneously.
    Type: Grant
    Filed: March 11, 2016
    Date of Patent: October 8, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji Ishihara, Masafumi Hita, Shinya Imura
  • Patent number: 10364547
    Abstract: The lifetime of an electrical storage device is prolonged by reducing a speed of at least relevant one of hydraulic actuators for a specific operation to be performed by a work machine. This hybrid work machine includes a limit control section. When at least one specific operation defined as predetermined one or more among a plurality of work operations performed by the hybrid work machine is performed under condition of a degree of tendency to deterioration of the electrical storage device becoming higher, the limit control section reduces a speed of at least relevant one of the hydraulic actuators at a rate preset for the specific operation depending on the degree of tendency to deterioration of the electrical storage device.
    Type: Grant
    Filed: January 11, 2017
    Date of Patent: July 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi Hita, Shinya Imura, Hidekazu Moriki
  • Patent number: 10364549
    Abstract: A motor-generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (12D) to (12F) in a working mechanism (12), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). An HCU (36) reduces outputs of the revolving electric motor (33), the revolving hydraulic motor (26), the boom cylinder (12D) and the like such that a ratio of a revolving speed of an upper revolving structure (4) and a movement speed of raising a boom (12A) is held to a ratio in a normal mode (NMODE) at the time of performing a compound movement of a revolving movement and a boom-raising movement in a low speed mode (LSMODE).
    Type: Grant
    Filed: January 19, 2016
    Date of Patent: July 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi Hita, Shinya Imura, Shiho Izumi, Hidekazu Moriki, Hiroaki Amano
  • Publication number: 20190211528
    Abstract: An HCU (37) includes a battery low temperature reducing output calculating section (71A) that determines, when it is determined that an electricity storage device (31) is in a low temperature state by a battery temperature Tb, a battery low temperature reducing output PbL that is made to a larger value as the battery temperature Tb is lower, a hydraulic oil low temperature reducing output calculating section (71B) that determines, when it is determined that hydraulic oil is in a low temperature state by a hydraulic oil temperature To, a hydraulic oil low temperature reducing output PoL that is made to a larger value as the hydraulic oil temperature To is lower, and an output command calculating section (80) that controls a vehicle body operation based upon a sum of the battery low temperature reducing output PbL and the hydraulic oil low temperature reducing output PoL.
    Type: Application
    Filed: November 6, 2017
    Publication date: July 11, 2019
    Inventors: Masafumi HITA, Shinya IMURA
  • Patent number: 10329737
    Abstract: An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: June 25, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi Hita, Shinya Imura, Shinji Nishikawa
  • Publication number: 20190186105
    Abstract: A work machine includes directional control valves 43 and 44 each controlling a direction and a flow rate of a pressurized fluid supplied to each a boom cylinder 32 and a bucket cylinder 36; operation amount sensors 51a, 52a, and 52b detecting operation amounts of operation devices 51 and 52; a variable flow control valve 45 that can restrict the flow rate of the pressurized fluid in a meter-in passage of the directional control valve 44 related to the bucket cylinder 36; and a controller 60 controlling the variable flow control valve on the basis of the detection results by the operation amounts from the operation amount sensors, and the controller changes over an action mode to any one of a normal mode for restricting the flow rate of the pressurized fluid by the variable flow control valve and a responsiveness priority mode for not restricting the flow rate of the pressurized fluid by the variable flow control valve in response to the detection results of the operation amounts of the plurality of operation
    Type: Application
    Filed: May 9, 2017
    Publication date: June 20, 2019
    Inventors: Shinya IMURA, Hiroaki AMANO, Shinji NISHIKAWA, Masafumi HITA
  • Publication number: 20190111773
    Abstract: It becomes possible to prevent deterioration of an electric storage device due to overdischarge of the electric storage device and engine stalling due to insufficient assist or disabled assist when a charge amount of the electric storage device falls, ensure that work is continuously conducted, suppress an operator from feeling discomfort in operation, and ensure favorable operability. A pump target output power computing section (21) computes present pump demanded power on the basis of work related information, limits the present pump demanded power in response to a degree of reduction of a state of charge of an electric storage device (12a) when the state of charge is lower than a preset threshold, and computes the limited present pump demanded power as present pump target output power.
    Type: Application
    Filed: September 29, 2016
    Publication date: April 18, 2019
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji NISHIKAWA, Shinya IMURA, Masafumi HITA, Hiroaki AMANO
  • Patent number: 10150465
    Abstract: A motor generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (11D) to (11F) in a working mechanism (11), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). The motor generator (27) and the revolving electric motor (33) are connected electrically to an electricity storage device (31). An HCU (36) sets a target electricity storage rate (SOC0) of the electricity storage device (31) and a pump output limit (POL0) of the hydraulic pump (23) corresponding to a mode selected by a mode selection device (38). The HCU (36) controls the engine (21), the motor generator (27), the revolving electric motor (33) and the electricity storage device (31) corresponding to the target electricity storage rate (SOC0) and the pump output limit (POL0).
    Type: Grant
    Filed: December 8, 2015
    Date of Patent: December 11, 2018
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi Hita, Seiji Ishida, Ken Takeuchi, Shinya Imura
  • Publication number: 20180282968
    Abstract: The lifetime of an electrical storage device is prolonged by reducing a speed of at least relevant one of hydraulic actuators for a specific operation to be performed by a work machine. This hybrid work machine includes a limit control section. When at least one specific operation defined as predetermined one or more among a plurality of work operations performed by the hybrid work machine is performed under condition of a degree of tendency to deterioration of the electrical storage device becoming higher, the limit control section reduces a speed of at least relevant one of the hydraulic actuators at a rate preset for the specific operation depending on the degree of tendency to deterioration of the electrical storage device.
    Type: Application
    Filed: January 11, 2017
    Publication date: October 4, 2018
    Inventors: Masafumi HITA, Shinya IMURA, Hidekazu MORIKI
  • Publication number: 20180282969
    Abstract: The invention provides a work machine that achieves high accuracy of forming a target construction surface and reduced fuel consumption. A trajectory corrective Pi pressure calculation section calculates a trajectory corrective pressure, which is a control signal for a boom cylinder, based on the distance from a front work device to a target construction surface such that the motion trajectory of the work device is maintained above the target construction surface. A power corrective Pi pressure calculation section calculates a power corrective pressure, which is a control signal for the boom cylinder, based on the bottom pressure of an arm cylinder when the difference between the target power and actual power of the arm cylinder is larger than a predetermined output power value. The boom cylinder is controlled based on the larger of the power corrective pressure and the trajectory corrective pressure while the arm cylinder is being operated.
    Type: Application
    Filed: November 24, 2017
    Publication date: October 4, 2018
    Inventors: Masafumi HITA, Kouichi SHIBATA
  • Publication number: 20180258613
    Abstract: A hybrid work machine that can suppress excessive limiting on pump absorption power even in a situation in which supply of electric power to an electric motor is limited is provided. The hybrid work machine includes: an engine 22; an assist generator motor 23 connected to the engine 22 in such a manner that a torque can be transmitted to the engine 22; an electric storage device 24 that supplies electric power to the assist generator motor 23; a monitoring device 28 that monitors the electric storage device 24 and that acquires electric storage device information; a hydraulic pump 41 driven by the engine 22 and the assist generator motor 23; and a pump regulator 43 that regulates a delivery flow rate of the hydraulic pump 41.
    Type: Application
    Filed: September 2, 2016
    Publication date: September 13, 2018
    Inventors: Hiroaki AMANO, Shinya IMURA, Ryouhei YAMASHITA, Shinji ISHIHARA, Shinji NISHIKAWA, Masafumi HITA
  • Patent number: 10060095
    Abstract: A hybrid work machine includes a controller and a temperature sensor that detects an electric storage device temperature. In a case where (Tp+Tc)?Te_min, the controller carries out a first comparison in which the controller compares a value of [(Tp+Tc)?Te_min] with a value of Ta_SOC, and the controller then selects a lower value of the first comparison. The controller then carries out a second comparison in which the controller compares the selected lower value of the first comparison with a value of [(Tp+Tc)?Te_max)]. The controller then sets a higher value of the second comparison as the torque of the assist motor Ta, wherein Tc is an accessory torque, Ta_SOC is an adjustment assist motor torque based on a current state of charge of the electric storage device, Ta is the torque of the assist motor, and Te_max is an engine maximum torque.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: August 28, 2018
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinya Imura, Masafumi Hita, Hiroaki Amano, Seiji Ishida, Ken Takeuchi, Itaru Naya, Chiaki Takahashi
  • Publication number: 20180238018
    Abstract: A control system for a construction machine maintains operability of a swing combined operation even when the power supplied from an engine or storage device varies. The control system includes a target path computation section that receives an operation amount of the front implement operation device, an operation amount of the swing operation device, a speed of the front implement drive unit detected, and an angular speed of the swing structure drive unit, and that computes a target path of a claw tip position of the front implement drive unit; and an actuator power computation section that regulates power supplied to the front implement drive unit or the swing structure drive unit in such a manner that a claw tip of the front implement drive unit follows the target path the front implement operation device and the swing operation device are operated simultaneously.
    Type: Application
    Filed: March 11, 2016
    Publication date: August 23, 2018
    Inventors: Shinji ISHIHARA, Masafumi HITA, Shinya IMURA
  • Patent number: 10047501
    Abstract: A control device of construction machine that performs tasks by driving a hydraulic pump by means of an electric motor that is driven by electric power of a battery device that is capable to charge and discharge and an engine that is mechanically coupled to the electric motor, includes: a charging/discharging control unit that controls the charging/discharging of the battery device in such a manner that, in case that a heavy load task where an output of the hydraulic pump is large and a light load task where the output of the hydraulic pump is small are alternately performed, when the output of the hydraulic pump during the heavy load task is increased or a time proportion of the heavy load task in the unit period is increased, an average value of charging current of the battery device per the unit period increases, and when the output of the hydraulic pump during the heavy load task is further increased or the time proportion of the heavy load task in the unit period is further increased, then the average va
    Type: Grant
    Filed: February 25, 2016
    Date of Patent: August 14, 2018
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji Ishida, Shinya Imura, Masafumi Hita
  • Patent number: 10030363
    Abstract: A hybrid work machine has an engine, an assist motor, a hydraulic pump which is driven by the total torque of the engine and the assist motor, and an electric storage device which accumulates electric power generated by the assist motor and supplies the electric power when the assist motor performs electric discharge. The continuous electric discharge from the electric storage device due to continuous operation at high load pressure can be suppressed without an operator experiencing an unusual operational characteristic. To this end, a pump flow rate correction control unit judges whether each hydraulic pump is in a high load operation state or not based on the output horsepower and/or the delivery pressure of each hydraulic pump and performs control such that the delivery flow rate gradually decreases when the hydraulic pump is in the high load operation state and this state continues beyond a predetermined time.
    Type: Grant
    Filed: February 10, 2016
    Date of Patent: July 24, 2018
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinya Imura, Shinji Nishikawa, Masafumi Hita, Hiroaki Amano
  • Publication number: 20180030690
    Abstract: An output command calculating section (40) of an HCU (36) restricts a battery discharge power from an electricity storage device (31) based upon a battery electricity storage rate (SOC) and a current square integrating rate (Risc) of the electricity storage device (31). Thereby, the HCU (36) transfers from a normal mode (NMODE) to a low speed mode (LSMODE) to lower a movement speed of a hydraulic actuator. A monitor display amount calculating section (50) of the HCU (36) calculates a maximum speed reduction rate (DRs) based upon a battery discharge power limit value (Plim0) and an engine output upper limit value (Pemax) from the output command calculating section (40). A monitor device (39) displays a reduction rate of the movement speed of the hydraulic actuator in the low speed mode (LSMODE) based on the maximum speed reduction rate (DRs).
    Type: Application
    Filed: February 22, 2016
    Publication date: February 1, 2018
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi HITA, Shinya IMURA, Shinji NISHIKAWA
  • Publication number: 20170356163
    Abstract: A motor-generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (12D) to (12F) in a working mechanism (12), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). An HCU (36) reduces outputs of the revolving electric motor (33), the revolving hydraulic motor (26), the boom cylinder (12D) and the like such that a ratio of a revolving speed of an upper revolving structure (4) and a movement speed of raising a boom (12A) is held to a ratio in a normal mode (NMODE) at the time of performing a compound movement of a revolving movement and a boom-raising movement in a low speed mode (LSMODE).
    Type: Application
    Filed: January 19, 2016
    Publication date: December 14, 2017
    Inventors: Masafumi HITA, Shinya IMURA, Shiho IZUMI, Hidekazu MORIKI, Hiroaki AMANO
  • Publication number: 20170291501
    Abstract: Provided is hybrid construction machine that can charge/discharge an electrical storage device appropriately and can suppress stop of an engine accompanying sharp increase of a load. The present invention includes a hybrid controller 22 that controls power of a hydraulic pump 17 and electric power of an inverter 15 in response to storage battery characteristics of the electrical storage device 16, and an output command unit 22F of the hybrid controller 22 is configured to control at least either one of the power of the hydraulic pump 17 and the electric power of the inverter 15 on the basis of at least either one of electric current or voltage of the storage battery characteristics and at least either one of temperature or a state of charge of the storage battery characteristics.
    Type: Application
    Filed: October 13, 2015
    Publication date: October 12, 2017
    Inventors: Chiaki TAKAHASHI, Shinya IMURA, Ken TAKEUCHI, Seiji ISHIDA, Itaru NAYA, Masafumi HITA
  • Publication number: 20170274891
    Abstract: A motor generator (27) is connected mechanically to an engine (21) and a hydraulic pump (23). The hydraulic pump (23) delivers pressurized oil to cylinders (11D) to (11F) in a working mechanism (11), a traveling hydraulic motor (25) and a revolving hydraulic motor (26). The revolving hydraulic motor (26) drives a revolving device (3) in cooperation with a revolving electric motor (33). The motor generator (27) and the revolving electric motor (33) are connected electrically to an electricity storage device (31). An HCU (36) sets a target electricity storage rate (SOC0) of the electricity storage device (31) and a pump output limit (POL0) of the hydraulic pump (23) corresponding to a mode selected by a mode selection device (38). The HCU (36) controls the engine (21), the motor generator (27), the revolving electric motor (33) and the electricity storage device (31) corresponding to the target electricity storage rate (SOC0) and the pump output limit (POL0).
    Type: Application
    Filed: December 8, 2015
    Publication date: September 28, 2017
    Inventors: Masafumi HITA, Seiji ISHIDA, Ken TAKEUCHI, Shinya IMURA