Patents Assigned to Hitachi Construction Machinery Co., Ltd.
  • Patent number: 11414831
    Abstract: A pair of right and left supporting bases (10) provided on a sidewalk (9) of a revolving body (4) and both right and left sides (16) of a movable ladder (12) are connected by trajectory restricting members (22) in a swingable manner. In positions of the left supporting base (10) which are apart from each other, main body base ends (20a and 21a) of first and second hydraulic cylinders (20 and 21) are pivotally supported, and rod tip ends (20b and 21b) of the respective hydraulic cylinders (20 and 21) are pivotally supported in a common position of the left side (16) of the movable ladder (12). By operating the first and second hydraulic cylinders (20 and 21) in directions reverse to each other (extension and retraction), in-common pivotally supported parts (20b and 21b) are moved, thereby switching a position of the movable ladder (12) between an extended position and a retracted position.
    Type: Grant
    Filed: June 20, 2018
    Date of Patent: August 16, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Hiroki Hamano
  • Patent number: 11414841
    Abstract: Provided are a work point position computing section configured to compute the relative position of a work point set on a bucket with respect to an upper swing structure on the basis of posture information, a target surface setting section configured to set a target surface as a target of excavation work on the basis of design surface information, a primary operation determining section configured to determine which of operations of a boom and an arm is a primary operation as a main operation when the work point is moved along the target surface, and a recommended operation computing section configured to compute a recommended operation amount and a recommended operation direction of a secondary operation as another operation different from the primary operation in the operations of the boom and the arm according to an operation amount and an operation direction of the primary operation.
    Type: Grant
    Filed: December 5, 2017
    Date of Patent: August 16, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Hidekazu Moriki, Hisami Nakano, Hiroshi Sakamoto
  • Patent number: 11414836
    Abstract: Provided is a work machine that, within the limit of not harming dynamic stability, can perform work utilizing the impact generated when a cylinder driving a front work implement collides with a stroke end.
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: August 16, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Yusuke Suzuki, Hiroshi Sakamoto, Mariko Mizuochi, Hiroaki Tanaka
  • Patent number: 11401696
    Abstract: An operator of a hydraulic excavator and a worker working outside of the hydraulic excavator carry a worker tag that sends a radio-wave signal including a magnetic field ID, a tag ID, and positional information obtained by a GNSS receiving section in case the worker tag receives a magnetic field signal generated by a magnetic field detecting device mounted on the hydraulic excavator. Based on positional information of the hydraulic excavator that is obtained from an GNSS receiving device and positional information of the worker tag, the position of the worker tag is calculated. In case the worker tag is detected in a proximity notification target area, a notification command is generated for notifying the operator of the hydraulic excavator of the detection of the worker tag, and output to a notification device in the cabin of the hydraulic excavator. Thus, a worker who is in proximity to the work machine is accurately detected, and the operator is prevented from being excessively alerted.
    Type: Grant
    Filed: December 13, 2018
    Date of Patent: August 2, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Mariko Mizuochi, Hiroshi Sakamoto, Kazushige Kurokami
  • Patent number: 11401695
    Abstract: Provided is a work machine capable of notifying that maintenance is necessary due to continuation of clogging in a cooling device or decrease in cooling performance. A wheel loader 1 including a radiator 31 and an oil cooler 32 comprises a controller 5, 5A configured to determine a clogging continuation state of the radiator 31 or the oil cooler 32. The controller 5, 5A determines whether clogging is occurring in the radiator 31 or the oil cooler 32 based on outside air temperature AW and cooling water temperature CW or hydraulic oil temperature HW, determines whether the clogging continues based on a clogging occurrence ratio R1, R2 while an engine 30 is operating, and outputs a notification command signal for providing the alarm buzzer 61 and the user management system 62 with a command to notify that maintenance is necessary when it is determined that the clogging continues.
    Type: Grant
    Filed: December 25, 2019
    Date of Patent: August 2, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Koji Hyodo, Masaki Yoshikawa, Kazuyuki Ito, Tetsuji Tanaka, Kouji Shimazaki, Isamu Aoki
  • Patent number: 11396872
    Abstract: A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle ?.
    Type: Grant
    Filed: November 3, 2017
    Date of Patent: July 26, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsuyoshi Yamada, Yoshitomo Yabuuchi, Naoyuki Okuno
  • Patent number: 11396839
    Abstract: A hydraulic drive fan control device is provided with a variable displacement hydraulic pump, a hydraulic motor, a hydraulic drive fan that is driven by the hydraulic motor, a flow amount control valve, a rotational speed detector that detects a rotational speed of an engine, and a controller. The controller outputs a first valve control signal to the flow amount control valve and outputs a first pump control signal to the hydraulic pump to rotate the hydraulic drive fan at a first rotational speed, and outputs a second valve control signal to the flow amount control valve and outputs a second pump control signal to the hydraulic pump, thereby stopping the rotation of the hydraulic drive fan.
    Type: Grant
    Filed: September 21, 2018
    Date of Patent: July 26, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takaaki Tanaka, Masatsugu Arai, Takayuki Sato, Naoki Fukuda, Jun Ikeda, Ryuji Kouno
  • Patent number: 11391017
    Abstract: A wheel loader is provided that can suppress abrupt change in vehicle speed accompanied by erroneous determination on a lift arm lifting operation. A wheel loader includes: an engine; an HST pump; an HST motor; a forward and reverse switch; a stepping amount sensor; an operation amount sensor; and a controller. The controller determines whether a specific condition for specifying an operation of the lift arm in an upper direction during forward travel of the vehicle body, on the basis of a forward and reverse switching signal, the stepping amount, and a pilot pressure pertaining to the lifting operation for the lift arm. In a case of the specific condition being satisfied, the vehicle speed is limited by controlling the displacement volume of the HST motor in conformity with increase in the pilot pressure.
    Type: Grant
    Filed: September 4, 2018
    Date of Patent: July 19, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Isamu Aoki, Tetsuji Tanaka, Masaki Nukii
  • Patent number: 11391011
    Abstract: A hydraulic excavator includes a controller (40) that executes region limiting control to forcibly raise a boom (8) in such a manner that a position of a tip end of a bucket (10) is kept on a target excavation surface and within a region above the target excavation surface if an operation device (45b, 46a) issues an action direction to an arm (9) or the bucket. The controller determines which is selected as a control mode over a raising speed of the boom at a time of executing region limiting control, a first mode or a second mode specified by a raising speed lower than a raising speed of the first mode if the tip end of the bucket is located below the target excavation surface, and controls the raising speed of the boom based on a result of determination.
    Type: Grant
    Filed: April 5, 2017
    Date of Patent: July 19, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Ryu Narikawa, Manabu Edamura, Kouji Ishikawa, Shiho Izumi
  • Patent number: 11391020
    Abstract: There is provided a work machine that can limit operation of a work device by MC, and improves the responsiveness of a hydraulic actuator to operation of an operation device by an operator, and ensures operability equivalent to that of a work machine that does not have MC functions, and allows the hydraulic actuator for which the operation device is not being operated to automatically operate in either direction of the operation directions thereof. For this purpose, a drive system includes a selector valve 203a disposed between a secondary port 134a of an operation device 45a and a flow control valve 15a and between a proportional solenoid valve 54a and the flow control valve 15a and a selector valve 203b disposed between a secondary port 134b of the operation device 45a and the flow control valve 15a and between a proportional solenoid valve 54b and the flow control valve 15a.
    Type: Grant
    Filed: May 20, 2020
    Date of Patent: July 19, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hiroki Ishii, Shinjiro Yamamoto, Masamichi Itou, Yasutaka Tsuruga, Shinya Imura
  • Patent number: 11384511
    Abstract: A wheeled work vehicle includes: a transmission transmitting the rotational power of a traveling hydraulic motor to wheels; a traveling control valve having an interruption position that interrupts supply of hydraulic fluid from a hydraulic pump to the traveling hydraulic motor; a shift changeover valve that shifts the speed stage of the transmission by the position of the shift changeover valve being selectively switched; and a controller that controls the traveling control valve and the shift changeover valve. The controller switches the traveling control valve to the interruption position, then switches the position of the shift changeover valve such that the speed stage of the transmission is shifted to the low speed stage, and switches the traveling control valve from the interruption position to an original position side before the switching in a case where the controller shifts the transmission from the high speed stage to the low speed stage.
    Type: Grant
    Filed: December 13, 2019
    Date of Patent: July 12, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventor: Kazuhiro Oouchi
  • Patent number: 11384509
    Abstract: A controller (25) of the hydraulic excavator (1) includes a signal separation section (150) that separates each of target speed signals for a plurality of front members (8, 9, 10) into a low frequency component and a high frequency component, a high fluctuation target speed calculation section (143) that allocates the separated high frequency components preferentially to a front member having a relatively small inertial load to calculate high fluctuation target speeds individually for the plurality of front members, a high fluctuation target actuator speed calculation section (141c) that calculates high fluctuation target speeds individually for the plurality of actuators from the high fluctuation target speeds for the plurality of front members, a low fluctuation target actuator speed calculation section (141b) that calculates low fluctuation target speeds individually for the plurality of actuators from the low frequency components separated by the signal separation section, and an actuator controller (200)
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: July 12, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Hisami Nakano, Hiroaki Tanaka, Yusuke Suzuki
  • Patent number: 11377813
    Abstract: In a work machine including a controller (500) configured to calculate respective target velocities of a hydraulic cylinder (5) for moving a plurality of work point candidates (8a and 8b) set to a work device along an optionally set target surface (60) on the basis of positional data of the target surface, posture data of the work device (15), and operation data of an operation lever (1), and control the velocity of the hydraulic cylinder (5) according to one of a plurality of the calculated target velocities, the controller calculates a candidate point velocity (VTab or VTba) occurring in a case where each of the plurality of work point candidates is moved at the corresponding target velocity (VTa or VTb) and occurring at a remaining work point candidate, selects a velocity at which an entry into the target surface is least likely from among the plurality of candidate point velocities, and controls the hydraulic cylinder according to the target velocity of the work point candidate associated with the selecte
    Type: Grant
    Filed: September 20, 2018
    Date of Patent: July 5, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Hisami Nakano, Hiroaki Tanaka, Yusuke Suzuki
  • Patent number: 11377822
    Abstract: A first torque control proportional electromagnetic valve (37) is connected through a first torque control line (41) to a third pressure receiving chamber (32D) in a first torque control regulator (32). A second torque control proportional electromagnetic valve (38) is connected through a second torque control line (42) to a third pressure receiving chamber (35D) in a second torque control regulator (35). The first and second torque control proportional electromagnetic valves (37, 38) are controlled by a controller 47. A switching valve (48) is provided between the first torque control line (41) and the second torque control line (42). The switching valve (48) supplies an output pressure of the first torque control proportional electromagnetic valve (37) to the third pressure receiving chamber (35D) in the second torque control regulator (35) at the time of driving hydraulic motors (2B, 2C) for left side and right side traveling.
    Type: Grant
    Filed: September 8, 2017
    Date of Patent: July 5, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kiwamu Takahashi, Kouji Ishikawa, Yasutaka Tsuruga, Masatoshi Hoshino, Seiji Hijikata
  • Patent number: 11371213
    Abstract: Provided is a wheel loader capable of moving up a lift arm in a short time during excavation work. A wheel loader comprises a controller configured to control maximum traction force of the wheel loader and input torque of a working device hydraulic pump, and include a specific condition determination section configured to determine whether a specific condition for specifying excavation work is satisfied, an elapsed time measurement section configured to measure an elapsed time from start of the excavation work, and an input torque control section configured to limit the input torque to a first input torque value when the specific condition is satisfied and increase the input torque from the first input torque value when a second set time elapses from the elapse of a first set time.
    Type: Grant
    Filed: December 26, 2018
    Date of Patent: June 28, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Koji Hyodo, Tetsuji Tanaka, Isamu Aoki, Kouji Shimazaki, Jumpei Kamiya
  • Patent number: 11371212
    Abstract: In a work machine including a solenoid valve that generates a pilot pressure to drive a directional control valve with use of the delivery pressure of a pilot pump as a source pressure, a shut-off valve that shuts off a hydraulic operating fluid from the pilot pump to the solenoid valve, a first sensor that senses the amount of operation of an operation lever, and a second sensor that senses a state amount relating to operation of the solenoid valve, whether or not an abnormality of the second sensor exists is determined on the basis of a sensing signal of the second sensor. When it is determined that the second sensor is abnormal, on the basis of a sensing signal of the first sensor, an opening command is made to the shut-off valve if operation of the operation lever is sensed, and a closing command is made to the shut-off valve if the neutral state of the operation lever is sensed.
    Type: Grant
    Filed: November 12, 2019
    Date of Patent: June 28, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoshiyuki Tsuchie, Kouichi Shibata
  • Patent number: 11352761
    Abstract: A work machine includes a controller (20) that performs an area restriction control for controlling at least one hydraulic cylinder (32a) of a plurality of hydraulic cylinders (32) in such a manner that a work device (400) is located on or on an upper side of an optionally set target surface (60) during operation of an operation lever (26). In the work machine, if a jack-up angle (?) as an inclination angle of a machine body (1A) relative to a ground is larger than a preset target value (?t), the controller, in performing the area restriction control, corrects the control of the at least one hydraulic cylinder (32a) in such a manner that the jack-up angle approaches the target value. The target value is set such as to vary according to posture of an arm (406).
    Type: Grant
    Filed: September 3, 2018
    Date of Patent: June 7, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Yusuke Suzuki, Hiroaki Tanaka, Hisami Nakano
  • Patent number: 11346081
    Abstract: Provided is a construction machine capable of driving each hydraulic actuator at a suitable speed while suppressing delivery flow rate of a hydraulic pump, both at a single operation time of driving each hydraulic actuator respectively singularly and at a combined operation time of simultaneously driving a plurality of hydraulic actuators.
    Type: Grant
    Filed: March 15, 2018
    Date of Patent: May 31, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Ryohei Yamashita, Kazushige Mori, Shinya Imura
  • Patent number: 11331605
    Abstract: A urea water tank (11) is provided with a unit insertion opening (12H) that is disposed on a top surface part (12A) of a tank body (12) and opens more largely than an external dimension (D2) of a sensor unit (20), a sensor mounting member (16) that is disposed on the top surface part (12A) of the tank body (12) and closes the unit insertion opening (12H), and a filter which is formed as a tubular body to surround the sensor unit (20), and inserted in the unit insertion opening (12H) of the tank body (12) from a lower end (24A4)-side, and having an upper end (24A3) mounted on the top surface part (12A) of the tank body (12) by using the sensor mounting member (16).
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: May 17, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hiroyuki Azuma, Nobuei Ariga, Tsuyoshi Noi
  • Patent number: 11332115
    Abstract: A power regeneration system of a work vehicle includes: a first generator (12) and a second generator (31) that are driven by an engine (11); a first electric circuit (C1) for supplying electric power to traveling motors (10L, 10R); a second electric circuit (C2) for supplying electric power to an auxiliary device (35); a voltage step down converter (21) providing electric power from the first electric circuit to the second electric circuit; and a controller (51) that determines whether a travel mode of the work vehicle is a powering mode or a regeneration mode in order to control driving of the voltage step down converter. If the travel mode is the regeneration mode, the controller provides the regenerative power from the first electric circuit through the voltage step down converter to the second electric circuit, in order to drive the auxiliary device with the regenerative power.
    Type: Grant
    Filed: June 4, 2018
    Date of Patent: May 17, 2022
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Shintarou Tanaka, Masatsugu Arai, Naoki Fukuda, Takaaki Tanaka, Yukiaki Shimizu