Patents Assigned to Hitachi Construction Machinery Co., Ltd.
  • Patent number: 10683632
    Abstract: A work vehicle includes: a main hydraulic pump that supplies pressure oil to a hydraulic cylinder; an accessory pump that supplies pressure oil to an auxiliary machine; and a confluence switching valve that merges pressure oil of the accessory pump with pressure oil of the main hydraulic pump. The work vehicle is provided with a control device that, in case atmospheric pressure or air density of outside air is lower than a predetermined value, executes confluence limitation control of reducing a confluence flow rate at the confluence switching valve compared to the time in case the atmospheric pressure or the air density of the outside air is higher than the predetermined value, and canceling the confluence limitation control in case rotation speed of an engine becomes higher compared to a predetermined rotation speed value during the confluence limitation control, and the rotation speed value is higher as the atmospheric pressure or the air density of the outside air is lower.
    Type: Grant
    Filed: September 28, 2016
    Date of Patent: June 16, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Atsushi Nakamura, Koji Shimazaki
  • 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: 10677272
    Abstract: Provided is a construction machine capable of detecting a stuck-open state of a surplus flow control valve in real time during operation without involving a reduction in the operational speed.
    Type: Grant
    Filed: June 26, 2017
    Date of Patent: June 9, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Teppei Saitoh, Juri Shimizu, Kenji Hiraku, Hiromasa Takahashi, Shouhei Sugiki
  • Patent number: 10669696
    Abstract: In a work vehicle provided with: a working device including an arm and a bucket; a vehicle speed detection device that detects a vehicle speed; a travel drive device that outputs a travel driving force increasing in response to a decrease in the vehicle speed at a time of excavation; and a control device that controls the travel driving force by the travel drive device, the control device is characterized by including a limit control section that limits the travel driving force during a specified time which passes from when the vehicle speed detected by the vehicle speed detection device becomes a predetermined first vehicle speed threshold value or less and the work vehicle plunges into an object to be excavated until an operation of the working device is started.
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: June 2, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuya Takeda, Hiroki Gotou, Kazuo Ishida, Yoshihiko Nakazawa
  • Patent number: 10669695
    Abstract: There is provided a hydraulic driving device for working machine having operability handling a change in burden weight in a front working device due to a loaded burden and the like when the working machine that accumulates energy in an accumulator and recovers and regenerates the energy performs an operation of lowering the front working device. A hydraulic driving device 5 includes a main pump 101, a boom cylinder 3, a tank 20, a flow rate control valve 6, an accumulator 300, a first differential pressure control valve 201, and a second differential pressure control valve 202. The first differential pressure control valve 201 is located between the boom cylinder 3 and the accumulator 300. The first differential pressure control valve 201 performs control on discharge oil from the boom cylinder 3 such that a differential pressure between before and after the flow rate control valve 6 becomes a target differential pressure.
    Type: Grant
    Filed: January 31, 2018
    Date of Patent: June 2, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masamichi Ito, Takatoshi Ooki
  • Patent number: 10668802
    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: Grant
    Filed: September 29, 2016
    Date of Patent: June 2, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji Nishikawa, Shinya Imura, Masafumi Hita, Hiroaki Amano
  • 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
  • Patent number: 10663575
    Abstract: An off-road dump truck includes a vehicle body, a peripheral recognition device, and an obstacle discrimination device. The peripheral recognition device detects obstacle candidates in front of the vehicle body. The obstacle discrimination device classifies the obstacle candidates, which were detected by the peripheral recognition device, into obstacles and non-obstacles and outputs, as obstacles, the obstacle candidates classified as obstacles. The obstacle discrimination device includes a travel state determination section, a distance filter section, and a reflection intensity filter section. The travel state determination section determines whether each obstacle candidate is a moving object or a stationary object. The distance filter section compares a distance, where the stationary object was first detected, with a distance threshold.
    Type: Grant
    Filed: September 8, 2016
    Date of Patent: May 26, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Atsushi Watanabe, Takuya Naka, Shinichi Uotsu, Koei Takeda
  • Patent number: 10662617
    Abstract: To reduce increase of the temperature of a control device of a supercharger and increase the lifetime of the control device of the supercharger, a work machine includes a variable geometry supercharger having changeable supercharge pressure and a working device. The work machine includes a variable displacement work hydraulic pump configured to be driven by an engine and supply pressure oil to an actuator configured to drive the working device; a supercharger control device configured to control the supercharger; a temperature detection device configured to detect the temperature of the supercharger control device; and a main control device configured to restrict, in case the temperature of the supercharger control device is higher than a first temperature, a maximum absorbing torque of the work hydraulic pump as compared to case the temperature of the supercharger control device is lower than the first temperature.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: May 26, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventor: Koji Hyodo
  • Patent number: 10655740
    Abstract: A work machine includes a closed circuit system in which there is provided a flushing valve.
    Type: Grant
    Filed: February 25, 2016
    Date of Patent: May 19, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Juri Shimizu, Teppei Saitoh, Kenji Hiraku, Yuki Akiyama, Hiromasa Takahashi
  • Patent number: 10656265
    Abstract: A mining work machine includes an obstacle determination device connected to a periphery detection device. If measurement points detected by the periphery detection device in a current cycle are equal to or greater than predetermined size thresholds equivalent in size to the mining work machine, these measurement points are put into a single obstacle candidate group. Based on relative speeds of the obstacle candidate at the measurement points and a traveling speed of the mining work machine, it is determined whether the obstacle candidate is a stationary object or a moving object, and whether the stationary object has been also detected by the periphery detection device in a preceding cycle. If a position of detection of the stationary object detected for the first time is equal to or smaller than a non-obstacle determination distance threshold, the obstacle determination device outputs the obstacle candidate as a non-obstacle.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: May 19, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventor: Shinichi Uotsu
  • Patent number: 10650251
    Abstract: In an industrial machine, the work safety is further improved by eliminating blind spots from an image displayed on a monitor. A hydraulic excavator 1 which is the industrial machine is equipped with monitoring cameras 15F, 15B, 15L, 15R mounted in the respective places of a revolving upperstructure 3 in order to capture images for monitoring. A monitor 20 displays camera images 21F, 21B, 21L, 21R obtained by the cameras as well as an icon image 21C of an image illustration of the hydraulic excavator 1. The cameras 15F, 15L, 15R are mounted at the distal ends of support arms 40F, 40L, 40R to be located in positions jutting from a revolving upperstructure main unit 3a of the revolving upperstructure 3, so that a hidden area under the underside of a catwalk 14 provided on the revolving upperstructure 3 falls within the field of view.
    Type: Grant
    Filed: October 12, 2018
    Date of Patent: May 12, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Yoichi Kowatari, Hidefumi Ishimoto, Moritaka Oota, Yoshihiro Inanobe, Hiroyoshi Tanaka, Kouji Fujita, Takashi Kusama
  • Patent number: 10640949
    Abstract: To make a reserve tank be hardly affected by the heat of an engine. An engine room (5) is totally covered by an exterior cover (9) including openings (44) at the upper surface, and includes in the inside thereof an engine (13), a radiator (24), a cooling fan (20) for sucking external air and cooling the radiator, and a reserve tank (30) for storing cooling water of the engine. The reserve tank (30) is disposed at a position above the engine (13) and facing the openings (44) and a position on the upstream side of the flow of the air with respect to the openings (44).
    Type: Grant
    Filed: March 10, 2016
    Date of Patent: May 5, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shigeru Hirasawa, Takeshi Hibiya, Toshikazu Kanno, Kazuhiko Mizoguchi
  • Patent number: 10640108
    Abstract: An on-board terminal device includes a location measuring section that measures a location of an own vehicle, a wireless communication section that transmits own vehicle information including location information of the own vehicle to other vehicles and receives other vehicle information including location information of the other vehicles from the other vehicles by execution of wireless communication with the other vehicles, and a monitoring section that estimates the location of the other vehicles and calculates a relative distance between the own vehicle and the other vehicles when the wireless communication has been interrupted, and executes an alarm process for preventing collision of the own vehicle and the other vehicles when the relative distance is less than a predetermined threshold.
    Type: Grant
    Filed: May 17, 2016
    Date of Patent: May 5, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiya Katou, Akiyoshi Kirimura, Takeshi Ito
  • Patent number: 10633830
    Abstract: A safety device for a construction machine includes a status information acquisition section that acquires status information pertaining to the status of the construction machine, a seat belt detection section that detects whether an operator is wearing a seat belt, and a control section that controls a warning section so that a warning is given on the basis of the status information when the operator is not wearing the seat belt, in which the status information includes information pertaining to the operation position of a gate lock lever that is manipulated to a lock position in which instructions from operating levers of the construction machine are disabled and a lock release position in which instructions from the operating levers are enabled, and the control section controls the warning section so that a warning is given when the gate lock lever operation position is at the lock release position.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: April 28, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuhiro Shibamori, Hidenobu Tsukada, Keiichiro Nakamura
  • Patent number: 10633825
    Abstract: The construction machine includes: a work implement driven by a first hydraulic actuator and a second hydraulic actuator; a first directional control valve controlling a flow rate and a direction of a hydraulic fluid supplied to the first hydraulic actuator; a first speed-up directional control valve provided in a second pump line and controlling a flow rate and a direction of a hydraulic fluid supplied to the first hydraulic actuator; a second directional control valve controlling a flow rate and a direction of a hydraulic fluid supplied to the second hydraulic actuator; an excavation load sensor that detects an excavation load imposed on the work implement; and a first speed-up control section that drives the first speed-up directional control valve, and the first speed-up control section is configured to control a driving amount of the first speed-up directional control valve in response to the excavation load.
    Type: Grant
    Filed: November 17, 2016
    Date of Patent: April 28, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hidekazu Moriki, Hiroshi Sakamoto, Hiroaki Tanaka, Yasutaka Tsuruga
  • Patent number: 10626575
    Abstract: A control system for a construction machine includes an electric lever operating device that outputs a command to a hydraulic actuator, a travel control lever device that outputs a command to a travel device, and a controller that outputs a drive command to a solenoid proportional valve that decompresses hydraulic fluid supplied from a pilot hydraulic source. The control system includes a machine body state judgment part that judges the state of the machine body based on an electric signal from the electric lever operating device and an operation amount of the travel control lever device and a dead zone calculation part that calculates a dead zone for the electric signal from the electric lever operating device based on the state of the machine body.
    Type: Grant
    Filed: February 23, 2016
    Date of Patent: April 21, 2020
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Hiroyuki Kobayashi, Hiroshi Sakamoto, Yoshiyuki Tsuchie, Hidekazu Moriki, Yasutaka Tsuruga
  • Patent number: 10625747
    Abstract: A device of estimating a slip angle of vehicle wheel has an attitude-toward-road surface estimation section that uses a series of distances to measurement points on a road surface to estimate vehicle-body-road-surface coordinate conversion information (VCCI) for conversion from a vehicle-body coordinate system to a road-surface coordinate system, an on-road-surface inertia quantity calculation section that removes a gravity acceleration component from the vehicle-body inertia quantity to obtain inertia quantity caused by motion of a vehicle body and uses the VCCI to convert from the inertia quantity caused by the motion of the vehicle body to the road-surface coordinate system, and a wheel slip angle estimation section that estimates a sideslip angle of the vehicle wheel on the basis of a difference between a wheel acceleration vector and the acceleration vector converted to the road-surface coordinate system.
    Type: Grant
    Filed: September 7, 2016
    Date of Patent: April 21, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Mikio Bando, Yukihiko Ono, Takayuki Satou, Hidefumi Ishimoto
  • Patent number: 10626578
    Abstract: A work machine has a controller which has an area limiting control section correcting the pilot pressures of pilot lines, a regeneration control section adjusting the flow rate of the hydraulic fluid caused to flow from a tank side line of an arm cylinder into a pump side line thereof between zero and a predetermined upper limit value, and a regeneration control switching section that issues an order to the regeneration control section to set the predetermined upper limit value to a first set value when the function of the area limiting control section is invalid and that issues an order to the regeneration control section to set the predetermined upper limit value to a second set value that is smaller than the first set value when the function of the area limiting control section is effective.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: April 21, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shiho Izumi, Ryuu Narikawa, Shuuichi Meguriya, Tarou Akita, Kouji Ishikawa
  • Patent number: 10619326
    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: Grant
    Filed: November 24, 2017
    Date of Patent: April 14, 2020
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masafumi Hita, Kouichi Shibata