Patents Assigned to Hitachi Construction Machinery Co., Ltd.
  • Patent number: 10280591
    Abstract: A work machine that can prevent restarting of an engine against a will of an operator from an idle stop state is provided. A hydraulic excavator includes a display device that displays a confirmation screen image for allowing an operator to confirm whether or not an engine is to be restarted from an idle stop state, and an inputting device that allows the operator to input a restart instruction for the engine in an interlocked relationship with the display of the confirmation screen image. A machine controller includes a restart controlling section that restarts the engine based on the restart instruction for the engine inputted by the inputting device.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: May 7, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoshiyuki Takigawa, Yasunori Ota, Shiho Izumi, Yuichiro Morita, Kouichi Shibata
  • Patent number: 10280593
    Abstract: Provided is a hydraulic fluid energy regeneration device for a work machine, including: a regeneration hydraulic motor driven by discharged return hydraulic fluid; a first hydraulic pump mechanically connected to the regeneration hydraulic motor; a second hydraulic pump that delivers an hydraulic fluid for driving a first hydraulic actuator and/or a second hydraulic actuator; a junction line that allows the hydraulic fluid delivered by the second hydraulic pump to be joined; a second regulator that regulates the delivery flow rate of the second hydraulic pump; and a first regulator that regulates the flow rate of the hydraulic fluid coming from the first hydraulic pump and flowing through the junction line.
    Type: Grant
    Filed: May 16, 2014
    Date of Patent: May 7, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji Hijikata, Kouji Ishikawa, Takatoshi Ooki, Shinya Imura
  • Patent number: 10280594
    Abstract: A hydraulic fluid energy regeneration system for a work machine capable of securely maintaining a brake pressure even when a solenoid valve or the like is erroneously rendered open by an electrical failure is provided.
    Type: Grant
    Filed: February 23, 2016
    Date of Patent: May 7, 2019
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Seiji Hijikata, Kouji Ishikawa, Shinya Imura
  • Patent number: 10274049
    Abstract: A reduction device (18) includes a fixed-side housing (19) accommodating a hydraulic motor (12) having an output shaft (16) and a rotating-side housing (21) rotated with respect to the fixed-side housing (19), and a first-stage planetary gear reduction mechanism (24) having a first sun gear (28) and a second-stage planetary gear reduction mechanism (32) having a second sun gear (33) are provided in the rotating-side housing (21). The first-stage planetary gear reduction mechanism (24) has a rotational shaft (25) having one side in an axial direction spline-connected with the output shaft (16), while the first sun gear (28) is provided on the other side in the axial direction of the rotational shaft (25). A small-diameter shaft (27B) is provided on the rotational shaft (25), and first and second half bushes (40, 41) are fitted with the small-diameter shaft (27B) from a radial direction.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: April 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takeshi Shinohara, Takeshi Shibukawa
  • Patent number: 10273656
    Abstract: The present invention includes a battery controller that calculates an electrical storage remaining amount of a battery, a charging/discharging request calculation part that calculates a charging/discharging request amount for keeping electric power outputted by the battery within a predetermined range based on the electrical storage remaining amount calculated, a target rotational speed calculation part that calculates a target rotational speed command value of a motor generator, and an inverter that controls the motor generator according to the target rotational speed command value calculated, and it is configured that at least one of the battery controller and the inverter calculates the actual charging/discharging amount of the battery, and that the target rotational speed calculation part calculates a target rotational speed correction value from difference between the charging/discharging request amount and the actual charging/discharging amount and corrects the target rotational speed command value.
    Type: Grant
    Filed: June 1, 2016
    Date of Patent: April 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Masatoshi Hoshino, Shinji Ishihara, Kentarou Itoga
  • Patent number: 10273658
    Abstract: The construction machine includes: a control valve that switchingly supplies hydraulic fluid from a hydraulic pump to a hydraulic actuator; a control valve drive device that supplies pilot secondary hydraulic fluid to the control valve in accordance with an operation of an operation lever device; a pilot hydraulic pump that supplies pilot primary hydraulic fluid to the control valve drive device; a pressure accumulation device that recovers return hydraulic fluid returned from the hydraulic actuator. The construction machine further includes: a check valve provided in a line between the pilot hydraulic pump and the control valve drive device; a pressure reducing valve that supplied the hydraulic fluid accumulated in the pressure accumulation device; a flow rate reduction device; and a controller that controls the flow rate reduction device in accordance with the pressure in the line between the check valve and the control valve drive device.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: April 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji Hijikata, Kouji Ishikawa, Yasutaka Tsuruga, Masatoshi Hoshino, Kiwamu Takahashi
  • Patent number: 10272813
    Abstract: One 3-position selector valve is used as a main control valve that controls hoist cylinders. A control valve is provided for supplying hydraulic oil from a low-pressure hydraulic pressure source to rod chambers of the hoist cylinders upon lowering a vessel. Provided between the rod chambers of the hoist cylinders and an oil tank is a check valve that enables to supply hydraulic oil from the oil tank to the rod chambers upon a vessel FLOAT operation. When an operation command from a control device is a vessel-lowering command, a controller switches the main control valve to a FLOAT position, and also switches the vessel LOWER operation control valve and supplies hydraulic oil of a low pressure from the low-pressure hydraulic pressure source to the rod chambers of the hoist cylinders.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: April 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Michio Fushiki
  • Publication number: 20190112786
    Abstract: A work machine pump control system includes: a pump horsepower control valve (22) which causes a first urging force determining a limited horsepower (F) of a hydraulic pump and a second urging force due to a delivery pressure of the hydraulic pump to act on a spool in opposition to each other and which controls the pump flow rate such that it does not exceed the limited horsepower (F); a target pump flow rate computation section (42) computing a target pump flow rate based on an operation pressure (px) and a load pressure (py); a target horsepower computation section (41) which computes a required horsepower (Freq) corresponding to an operation pressure (px) from a relationship related to the operation pressure (px) and which computes a target horsepower (Ftar) based on the required horsepower (Freq); and a pump horsepower control section (35) which controls the pump horsepower control valve (22) such that the target pump flow rate (Qtar) is delivered with the limited horsepower (F) determined by the pump hor
    Type: Application
    Filed: September 28, 2016
    Publication date: April 18, 2019
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shinji NISHIKAWA, Shinya IMURA, Hidekazu MORIKI, Hiroaki AMANO
  • 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: 10253481
    Abstract: The present invention includes: a map information storage unit 18 storing map data 18A representing a travelable area for a dump truck 7; a work machine information accumulation unit 19 accumulating position data 6A and operational data 6B of a hydraulic excavator 6; an operational range arithmetic processing unit 21 calculating an operational range of the hydraulic excavator 7 on the basis of the position data 6A and the operational data 6B accumulated in the work machine information accumulation unit 19; and a map information update unit 22 verifying the operational range of the hydraulic excavator 6 calculated by the operational range arithmetic processing unit 21 against the map data 18A stored in the map information storage unit 18 in order to correct the boundary 18a of the loading site 1 in the map data 18A and then update the map data 18A.
    Type: Grant
    Filed: October 28, 2015
    Date of Patent: April 9, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Manabu Katou, Hiroto Morizane, Yukihiro Kawamata
  • Patent number: 10253479
    Abstract: When option attachment has not been attached, a reserve flow/direction control valve 8 is made to operate as a center bypass cut valve. When an option attachment has been attached, switching control is performed. In the switching control, when the option attachment is not used, the reserve flow/direction control valve 8 is made to operate as a center bypass cut valve for adjusting composite opening area of a center bypass and thereby controlling the flow rate of hydraulic fluid flowing into an actuator. When the option attachment is used, the reserve flow/direction control valve 8 is made to operate so as to supply the hydraulic fluid to an option hydraulic actuator 14.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: April 9, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd
    Inventors: Tomoaki Kaneta, Kouji Ishikawa, Hidetoshi Satake, Shinya Imura
  • Patent number: 10255811
    Abstract: On a basis of a relative position of an obstacle 401, a size of the obstacle in an own vehicle 12 width direction and a width of the own vehicle 12, a maximum amount Dt of movement of the own vehicle 12 in the vehicle width direction as required to avoid the obstacle 401 is calculated. A point displaced over the maximum amount of movement toward a side of the adjacent lane from the relative position of the obstacle 401 is determined as an avoiding point 250. If a distance d between the avoiding point 250 and the adjacent lane is greater than the width Wm of the own vehicle 12, an avoiding path is generated for allowing the own vehicle 12 to pass the avoiding point 250.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: April 9, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takuya Naka, Masaki Kanai, Takayuki Satou
  • Patent number: 10248128
    Abstract: A haulage vehicle comprises: a position calculating system (220) calculating an estimated position of its own vehicle; a position range calculating unit (201b) calculating a position range which is centered around the estimated position and in which the haulage vehicle is present with a predetermined expected probability; a maximum deviation amount calculating unit (602) calculating a maximum deviation amount indicating a highest value among the amounts of deviations between a target route of the haulage vehicle and each of points included in the position range; a target vehicle-speed decision unit (603) setting a target vehicle speed of the haulage vehicle to be relatively low when the maximum deviation amount is relatively large; and a target route-tracing unit (201g) performing control for the haulage vehicle to travel along the target route in compliance with the target vehicle speed.
    Type: Grant
    Filed: March 3, 2015
    Date of Patent: April 2, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Wataru Tanaka, Shinjiro Saito, Mikio Bando, Masanori Ichinose
  • Patent number: 10244456
    Abstract: A wireless communication system includes an on-board terminal equipment mounted on a working machine, and a control server communicably connected together via a network including a first wireless base station and a second wireless base station. The control server sets a zone of a travel route as a travel-permitted zone, for which a travel permission has been given only to the working machine. A permission requesting zone in the travel-permitted zone, in which the working machine makes a setting request to the control server for a new travel-permitted zone, is set as a no-handover zone in which switching of the connected base station from the first wireless base station to the second wireless base station is prohibited. The on-board terminal equipment switches the first wireless base station to the second wireless base in a zone other than the no-handover zone in the travel-permitted zone.
    Type: Grant
    Filed: June 2, 2016
    Date of Patent: March 26, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Ryota Yamasaki, Tomoyuki Hamada, Akiyoshi Kirimura, Tsutomu Yamada
  • Patent number: 10232775
    Abstract: An electric drive vehicle is provided with first and second slider plates contacting a trolley line on the high-voltage side and on the ground side, respectively. A camera has a photographing range of the whole of the second slider plate held in contact with the trolley line on the ground side and a part of the trolley line residing around the second slider plate. A controller controls a display of a monitor, wherein the controller includes a relative distance calculation section that calculates a relative distance between the trolley line on the ground side and a reference position of the second slider plate, and a bird's eye view image data generation section that generates bird's eye view image data reflecting the relative distance calculated by the relative distance calculation section and that outputs the bird's eye view image data to the monitor.
    Type: Grant
    Filed: January 19, 2017
    Date of Patent: March 19, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoshiaki Tsutsumi, Naoki Tatsuzawa
  • Patent number: 10235658
    Abstract: The maintenance management device 3 includes an error status diagnosis unit 11, a grace period estimation unit 14, a maintenance cost estimation unit 15, and a screen display unit 17. When the error status diagnosis unit 11 has diagnosed the occurrence of an anomaly, the grace period estimation unit 14 estimates a first grace period leading up to the occurrence of a failure. The maintenance cost estimation unit 15 estimates the cost of corrective maintenance incurred when the failure occurs after the elapse of the first grace period. The screen display unit 17 displays a combination of the first grace period and the cost of corrective maintenance. Alternatively, the grace period estimation unit 14 estimates a second grace period over which preventive maintenance may be postponed without a failure.
    Type: Grant
    Filed: July 10, 2013
    Date of Patent: March 19, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hideaki Suzuki, Kozo Nakamura, Shinya Yuda, Munetoshi Unuma, Junsuke Fujiwara, Takayuki Uchida, Katsuaki Tanaka, Mitsuo Aihara, Teruo Nakamura, Nobuyoshi Hirowatari, Hiroshi Ogura
  • Patent number: 10233822
    Abstract: An expansion tank, while maintaining gas-liquid separation performance of coolant circulating through an engine cooling apparatus, can absorb pressure variations occurring with volume change of the coolant even when an excessive amount of coolant is supplied. A bulkhead 42 partitions an expansion tank 30 into separate chambers R1 to R6 that communicate with each other via a first communication hole 44 positioned lower than a FULL line. The separate chambers R4 to R6 that constitute a separate chamber group X communicate with each other via a third communication hole 45a positioned higher than the FULL line. The separate chambers R1 to R3 that constitute a separate chamber group Y communicate with each other via a fourth communication hole 45b positioned higher than the FULL line. The separate chamber R1 and the separate chamber R4 communicate with each other via a second communication hole 45c disposed at the height of the FULL line.
    Type: Grant
    Filed: January 19, 2016
    Date of Patent: March 19, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hitoshi Nishiguchi, Tomoyuki Saito
  • Patent number: 10228454
    Abstract: Provided is an obstacle detection device for a work machine which can detect an obstacle coming close to a vehicle accurately regardless of vehicle speed. In the present invention, an obstacle detection device 10 for a dump truck 1 which detects an obstacle coming close to the vehicle includes: a periphery monitoring unit 11 for detecting an obstacle in the area around the vehicle and monitoring the area around the vehicle; a distant monitoring unit 12 for detecting an obstacle in a more distant place from the vehicle than the detection range of the periphery monitoring unit 11 and monitor a distant area from the vehicle; and a monitoring switching unit 13 for switching between monitoring by the periphery monitoring unit 11 and monitoring by the distant monitoring unit 12.
    Type: Grant
    Filed: January 15, 2015
    Date of Patent: March 12, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Shinichi Uotsu
  • Patent number: 10227997
    Abstract: To provide a hydraulic drive system for a work machine capable of securing a favorable operability in the case where hydraulic fluid discharged from a hydraulic actuator is regenerated for driving other hydraulic actuator.
    Type: Grant
    Filed: September 16, 2015
    Date of Patent: March 12, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Seiji Hijikata, Kouji Ishikawa, Shinya Imura
  • Patent number: D847213
    Type: Grant
    Filed: February 27, 2018
    Date of Patent: April 30, 2019
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Shosei Kurosaka, Takumi Tanba, Shigeru Hirasawa, Kazuhiko Mizoguchi