Patents by Inventor Akihiro Narazaki

Akihiro Narazaki 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: 20220349153
    Abstract: Both a control for limiting operation of a machine body and a control for raising engine speed are achieved when an obstacle is detected. To this end, a machine controller performs operation limiting control by conducting a control for reducing the speed of the engine when the machine body does not require engine speed increase control and an obstacle is sensed by obstacle sensors, and the machine controller performs supply flow rate reduction control for reducing the flow rates of the hydraulic fluid supplied to hydraulic actuators from a hydraulic pump when the machine body requires the engine speed increase control and an obstacle is sensed by the obstacle sensors.
    Type: Application
    Filed: December 10, 2020
    Publication date: November 3, 2022
    Inventors: Ryota KAMEOKA, Shinji NISHIKAWA, Akihiro NARAZAKI
  • Publication number: 20220333348
    Abstract: Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.
    Type: Application
    Filed: March 18, 2021
    Publication date: October 20, 2022
    Inventors: Kento KUMAGAI, Shinya IMURA, Yasutaka TSURUGA, Takaaki CHIBA, Hiroaki AMANO, Shinji NISHIKAWA, Akihiro NARAZAKI, Genroku SUGIYAMA, Shinjiro YAMAMOTO
  • Publication number: 20220333352
    Abstract: Provided is a work machine which can achieve both of excellent operability when an operator manually operates a machine body or a work device and an accuracy of control of the machine body or the work device when a controller performs automatic control. The controller is configured to, in a case where the automatic control function selector switch gives an instruction to disable the automatic control function, adjust an opening amount of a bleed-off valve to a maximum opening amount or an opening amount corresponding to input amounts of control levers, and in a case where the automatic control function selector switch gives the instruction to enable the automatic control function, adjust the opening amount of the bleed-off valve, in at least part of an operation region of the control levers, so as to be smaller than the opening amount with the instruction to disable the automatic control function being given.
    Type: Application
    Filed: November 2, 2020
    Publication date: October 20, 2022
    Inventors: Kento KUMAGAI, Shinya IMURA, Yasutaka TSURUGA, Takaaki CHIBA, Hiroaki AMANO, Shinji NISHIKAWA, Akihiro NARAZAKI, Genroku SUGIYAMA
  • Publication number: 20220333356
    Abstract: Provided is a construction machine that avoids automatic release of operation restriction involving, for example, sudden acceleration unintended by an operator even when an inclined angle of a vehicle body changes. The construction machine includes a vehicle body 50 configured to operate, 3D sensors (obstacle detection devices) 5, 6, 7, and 8 that detect an obstacle present around the vehicle body 50, an inclined angle determination device (an inclined angle detection device) 9 that detects the inclined angle of the vehicle body 50, and a vehicle body controller (a controller) 14 having an operation restriction function that performs a restriction control to restrict an operation of the vehicle body 50 when the 3D sensors (the obstacle detection devices) 5, 6, 7, and 8 detect an obstacle.
    Type: Application
    Filed: October 28, 2020
    Publication date: October 20, 2022
    Inventors: Ryota KAMEOKA, Shinji NISHIKAWA, Akihiro NARAZAKI
  • Publication number: 20220290406
    Abstract: A work machine that can keep the control accuracy of actuators irrespective of temperature variation of a hydraulic operating fluid that passes through flow rate controllers that control the flow rates of supply to the actuators is provided. For this purpose, the flow rate controllers each have a valve body that is disposed on a main hydraulic line connecting a delivery line of a hydraulic pump and the actuator and that moves according to an operation pressure from a solenoid proportional pressure reducing valve, a sampling hydraulic line that branches from the main hydraulic line, and a temperature sensor set on the sampling hydraulic line. The controller is configured to correct a command electrical signal to the solenoid proportional pressure reducing valve according to a signal from the temperature sensor.
    Type: Application
    Filed: March 12, 2021
    Publication date: September 15, 2022
    Inventors: Kento KUMAGAI, Shinya IMURA, Yasutaka TSURUGA, Takaaki CHIBA, Hiroaki AMANO, Shinji NISHIKAWA, Akihiro NARAZAKI
  • Publication number: 20220290411
    Abstract: In a hydraulic excavator 1 including a machine body 1B and a front work device 1A, when an object is detected by sensors 13a, 13b, and 13c for detecting an object around the machine body 1B, when operation limiting control for limiting the operation of at least one of the machine body 1B and the front work device 1A is enabled, or when an operation device 4 is operated, the detection of the object is notified to an operator by a first state warning, and when the operation limiting control is enabled and when the operation device 4 is not operated, the detection of the object is notified to the operator by a second state warning that is weaker in warning intensity than the first state warning. Accordingly, the botheration for the operator can be suppressed while securing the effectiveness of an alarm in periphery monitoring, and the safety performance can be enhanced.
    Type: Application
    Filed: October 28, 2020
    Publication date: September 15, 2022
    Inventors: Keiichirou ANAHARA, Naoki HAGIWARA, Kazuhiko MIZOGUCHI, Akihiro NARAZAKI, Shinji NISHIKAWA
  • Publication number: 20220282450
    Abstract: Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value.
    Type: Application
    Filed: August 28, 2020
    Publication date: September 8, 2022
    Inventors: Hiroaki AMANO, Kento KUMAGAI, Shinji NISHIKAWA, Akihiro NARAZAKI
  • Publication number: 20220275604
    Abstract: Provided is a remote control system for work machine capable of enhancing the stability and efficiently improving the operability. A remote control system for a work machine having a plurality of actuators 31 corrects all command signals for the actuators 31 being operated when a communication delay time occurs during operation with the actuators 31. This limits the operation of the actuators 31 while keeping the ratio of the command signals (operation signals) of the actuators 31.
    Type: Application
    Filed: March 10, 2021
    Publication date: September 1, 2022
    Inventors: Teruki IGARASHI, Kento KUMAGAI, Akihiro NARAZAKI
  • Publication number: 20220267998
    Abstract: There is provided a construction machine that achieves both safety and operability by lowering the possibility of an accident due to contact between the construction machine and a worker in the periphery of a vehicle body while securing operability in situations where an object required for work is present in the periphery. A controller has a normal mode as a control mode for making the operation limiting control effective and a temporary cancelation mode as a control mode for temporarily canceling the operation limiting control. The controller shifts to the temporary cancelation mode in response to operation of the control canceling device while in the normal mode. The controller shifts back to the normal mode in a case where a predetermined condition not responsive to operation of the control canceling device is satisfied while in the temporary cancelation mode.
    Type: Application
    Filed: June 11, 2020
    Publication date: August 25, 2022
    Inventors: Shinji NISHIKAWA, Koji SHIWAKU, Shinjiro YAMAMOTO, Ryota KAMEOKA, Akihiro NARAZAKI
  • Publication number: 20220220694
    Abstract: In a hydraulic excavator including a main controller that can execute area restriction control, the main controller is configured to calculate an operation velocity Vfx of a front work device in a machine body coordinate system and a movement velocity (dragging velocity) Vu of a machine body in a gravity coordinate system and correct a direction of a calculated target velocity vector Vt upward away from a construction target surface when generation of dragging is detected during execution of the area restriction control based on the calculated operation velocity Vfx of the front work device 2 and the calculated movement velocity Vu of the machine body.
    Type: Application
    Filed: August 3, 2020
    Publication date: July 14, 2022
    Inventors: Yusuke SUZUKI, Hiroaki TANAKA, Hisami NAKANO, Hiroshi SAKAMOTO, Akihiro NARAZAKI
  • Publication number: 20220186459
    Abstract: A hydraulic actuator includes a control valve unit that controls a flow of a hydraulic fluid supplied from a hydraulic pump to a plurality of hydraulic actuators, a plurality of control lever devices that output a pilot pressure actuating the control valve unit, with use of a discharged pressure from a pilot pump as a source pressure, a solenoid valve unit including a plurality of solenoid pressure reducing valves connected between the plurality of control lever devices and the control valve unit, and a controller configured to calculate velocity limits for the plurality of hydraulic actuators on the basis of signals from a plurality of posture sensors and control openings of the solenoid pressure reducing valves, in which the controller is configured to control the openings of the solenoid pressure reducing valves for arm crowding and arm dumping to be larger than an opening based on the velocity limits while a boom raising operation signal is being output from the control lever devices.
    Type: Application
    Filed: June 18, 2020
    Publication date: June 16, 2022
    Inventors: Teruki IGARASHI, Akihiro NARAZAKI, Masamichi ITOU
  • Publication number: 20220186458
    Abstract: When an operation amount of an operation lever corresponding to a boom cylinder is equal to or smaller than an operation amount of an operation lever corresponding to an arm cylinder, an estimated velocity of the arm cylinder used for region limiting control is computed on the basis of a first condition defining, in advance, a relation between the operation amount of the operation lever and the estimated velocity of the arm cylinder. When the operation amount of the operation lever corresponding to the boom cylinder is larger than the operation amount of the operation lever corresponding to the arm cylinder, the estimated velocity of the arm cylinder used for the region limiting control is computed as a velocity higher than the estimated velocity of the arm cylinder computed on the basis of the first condition. The behavior of the work device can thereby be stabilized.
    Type: Application
    Filed: September 29, 2020
    Publication date: June 16, 2022
    Inventors: Tarou AKITA, Takahiro KOBAYASHI, Akihiro NARAZAKI, Masamichi ITO
  • Publication number: 20220154742
    Abstract: A main controller generates a supplemented design face that passes through a junction or above the junction between a first design face and a second design face adjacent to each other, among a plurality of design faces, the supplemented design face having one end thereof positioned on the first design face and another end thereof positioned on the second design face, sets a curvature 1/R of the supplemented design face according to an arm operation amount of an operation lever device, and executes semi-automatic excavation control to control a boom cylinder with one of the faces included in the supplemented design face being set as the target face.
    Type: Application
    Filed: September 4, 2020
    Publication date: May 19, 2022
    Inventors: Hisami NAKANO, Hiroaki TANAKA, Yusuke SUZUKI, Akihiro NARAZAKI
  • Publication number: 20220145580
    Abstract: A work machine includes a work device having a boom, an arm, and work equipment and a controller that sets a target surface, and calculates a work equipment-to-target surface distance on the basis of signals from a position sensor and a posture sensor, and controls the boom and carries out deceleration control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when operation of the arm is carried out and the work equipment-target surface distance has become shorter than a predetermined distance.
    Type: Application
    Filed: September 8, 2020
    Publication date: May 12, 2022
    Inventors: Teruki IGARASHI, Akihiro NARAZAKI, Shuuichi MEGURIYA
  • Patent number: 11274419
    Abstract: In a specific state where the raising operation of a boom 25 and the swing operation of an upperstructure 21 are performed at the same time to supply a hydraulic oil from a first pump 2 to a cylinder 7a through a first valve 6a, and to supply the same from a second pump 3 to a motor 7b through a second valve 6b, a controller 10 outputs the command current for opening a valve 13, and supplies a part of the hydraulic oil supplied to the motor 7b from the second pump 3 to the cylinder 7a through the third valve 6c when the motor 7b does not reach a steady swing state, and outputs a command current for closing the valve 13 when the motor 7b is in the steady swing state.
    Type: Grant
    Filed: September 27, 2018
    Date of Patent: March 15, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shu Shirato, Yoshihiro Shirakawa, Akihiro Narazaki, Katsuaki Kodaka
  • Publication number: 20220025608
    Abstract: When a bucket 10 is grounded on soil, an operation signal is outputted or corrected such that a relative angle of the bucket 10 with respect to a target surface is maintained if a distance D between the bucket 10 and the target surface 60 is equal to or less than a preset first threshold value D1. When the bucket 10 is not grounded on soil, the operation signal is outputted or corrected such that the relative angle of the bucket 10 with respect to the target surface 60 is maintained if the distance between the bucket 10 and the target surface 60 is equal to or less than a preset second threshold value D2 set smaller than the first threshold value D1. As a result, control to maintain an angle of a work tool can be suitably started.
    Type: Application
    Filed: November 29, 2019
    Publication date: January 27, 2022
    Inventors: Masamichi ITOH, Teruki IGARASHI, Akihiro NARAZAKI
  • Publication number: 20210285185
    Abstract: In a specific state where the raising operation of a boom 25 and the swing operation of an upperstructure 21 are performed at the same time to supply a hydraulic oil from a first pump 2 to a cylinder 7a through a first valve 6a, and to supply the same from a second pump 3 to a motor 7b through a second valve 6b, a controller 10 outputs the command current for opening a valve 13, and supplies a part of the hydraulic oil supplied to the motor 7b from the second pump 3 to the cylinder 7a through the third valve 6c when the motor 7b does not reach a steady swing state, and outputs a command current for closing the valve 13 when the motor 7b is in the steady swing state.
    Type: Application
    Filed: September 27, 2018
    Publication date: September 16, 2021
    Inventors: Shu SHIRATO, Yoshihiro SHIRAKAWA, Akihiro NARAZAKI, Katsuaki KODAKA
  • Patent number: 11001985
    Abstract: A controller for a hydraulic excavator includes a first speed computation section that calculates a first speed of an arm cylinder from a value detected by an operation amount sensor; a second speed computation section that calculates a second speed from a value detected by a posture sensor and a third speed computation section calculates a third speed that is used as the speed of the arm cylinder in an actuator control section adapted to execute MC (machine control). The third speed computation section calculates the first speed as the third speed during the period between the detection of an input of operation for an arm by the operation amount sensor and predetermined time to, the third speed as a speed calculated from the first speed and the second speed during the period between t0 and time t1, and the second speed as the third speed at and after time t1.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: May 11, 2021
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Masamichi Ito, Hisami Nakano, Yusuke Suzuki, Akihiro Narazaki, Teruki Igarashi
  • Patent number: 10677268
    Abstract: In a construction machine with a hydraulic pilot type hydraulic control device, occurrence of jerking is prevented. A hydraulic excavator 1 having hydraulic pumps 51L and 51R, travel motors 22L and 22R, traveling operating levers 34L and 34R, a pilot pump 54, hydraulic pilot valves 55La, 55Lb, 55Ra, and 55Rb, and directional control valves 53L and 53R includes: changeover switches 35L and 35R which change the operating mode of the traveling operating levers 34L and 34R; pilot pressure adjusting devices 5L and 5R which adjust the pilot pressure applied to the directional control valves 53L and 53R; and pilot pressure sensors 56La, 56Lb, 56Ra, and 56Rb. The pilot pressure adjusting devices apply the pilot pressure at the time when the operating mode of the traveling operating levers 34L and 34R is changed to a control mode, to the directional control valves 53L and 53R.
    Type: Grant
    Filed: February 20, 2018
    Date of Patent: June 9, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Daiki Itou, Akihiro Narazaki, Katsuaki Kodaka
  • Patent number: 10662618
    Abstract: To prevent increase/decrease in pump flow rate due to load variation with change in the posture of a work attachment and improve the operability in arm pushing operation.
    Type: Grant
    Filed: February 21, 2018
    Date of Patent: May 26, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tomoaki Kaneta, Akihiro Narazaki, Katsuaki Kodaka