公开(公告)号：US20220333352A1

公开(公告)日：2022-10-20

申请号：US17640947

申请日：2020-11-02

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Yasutaka TSURUGA ,  Takaaki CHIBA ,  Hiroaki AMANO ,  Shinji NISHIKAWA ,  Akihiro NARAZAKI ,  Genroku SUGIYAMA

IPC: E02F9/22 ,  E02F9/20

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.

公开(公告)号：US20220290406A1

公开(公告)日：2022-09-15

申请号：US17637533

申请日：2021-03-12

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Yasutaka TSURUGA ,  Takaaki CHIBA ,  Hiroaki AMANO ,  Shinji NISHIKAWA ,  Akihiro NARAZAKI

IPC: E02F9/22 ,  E02F9/26 ,  E02F9/20 ,  F15B13/044 ,  F15B13/02

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.

公开(公告)号：US20210340731A1

公开(公告)日：2021-11-04

申请号：US16330407

申请日：2017-09-08

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kiwamu TAKAHASHI ,  Kouji ISHIKAWA ,  Yasutaka TSURUGA ,  Masatoshi HOSHINO ,  Seiji HIJIKATA

IPC: E02F9/22

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.

公开(公告)号：US20210317636A1

公开(公告)日：2021-10-14

申请号：US17268717

申请日：2019-07-11

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Akira KANAZAWA ,  Hidekazu MORIKI ,  Shinya IMURA ,  Yasutaka TSURUGA ,  Takaaki CHIBA

IPC: E02F9/22 ,  F15B11/028 ,  F15B11/042 ,  F15B11/044 ,  F15B19/00

Abstract: A construction machine that precisely enables derivation of the operation characteristics of hydraulic actuators in a high-velocity area with less calibration operation is provided. A controller (10) has a calibration mode in which the controller (10) derives operation characteristics (α(xs)) representing a relation among a spool position (xs) of a meter-in valve (8a1), an operation velocity (Va) of a hydraulic actuator (4a), and a differential pressure (ΔP) across the meter-in valve (8a1), and is configured to, in a case where the spool position (xs) of the meter-in valve (8a1) has changed in a direction to increase the opening area of the meter-in valve (8a1) in the calibration mode, output a command signal to increase the opening area of a bleed-off valve (8b1) to a bleed-off solenoid proportional pressure-reducing valve (8b2) as a command signal to reduce the differential pressure (ΔP).

公开(公告)号：US20210254309A1

公开(公告)日：2021-08-19

申请号：US17252129

申请日：2019-03-28

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Kento KUMAGAI ,  Shinya IMURA ,  Genroku SUGIYAMA ,  Katsuaki KODAKA ,  Yasutaka TSURUGA ,  Takaaki CHIBA

IPC: E02F9/22

Abstract: A work machine capable of driving each actuator more speedily and more accurately by ensuring high operability in a case of operator's manual operation, while accurately supplying a hydraulic fluid at a target flow rate to the actuator without depending on a load fluctuation in a case of automatic control over a machine body in response to a command input from a controller is provided.
The controller controls a plurality of auxiliary flow controllers in such a manner that supply flow rates to a plurality of directional control valves from hydraulic pumps fluctuate in response to load fluctuations of a plurality of hydraulic actuators in a case in which an instruction on invalidation of an area limiting control function is issued, and controls the plurality of auxiliary flow controllers in such a manner that the supply flow rates to the plurality of directional control valves from the hydraulic pumps do not fluctuate in response to the load fluctuations of the plurality of hydraulic actuators in a case in which an instruction on validation of the area limiting control function is issued.

公开(公告)号：US20190338494A1

公开(公告)日：2019-11-07

申请号：US16074132

申请日：2016-11-17

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Hidekazu MORIKI ,  Hiroshi SAKAMOTO ,  Hiroaki TANAKA ,  Yasutaka TSURUGA

IPC: E02F9/22 ,  E02F3/43 ,  F15B11/028 ,  F15B11/044 ,  F15B11/17 ,  F15B11/08

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.

公开(公告)号：US20200010060A1

公开(公告)日：2020-01-09

申请号：US16490249

申请日：2018-07-27

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Takaaki TANAKA ,  Takanobu IKARI ,  Yasutaka TSURUGA ,  Takayuki SATO ,  Takashi SASAKI

IPC: B60T7/16 ,  B60T13/14 ,  B60T13/68 ,  B60T17/18 ,  F15B20/00

Abstract: An automatic brake subsystem (24) includes second accumulators (25F, 25R), a front second line (28) and a rear second line (29), second brake valves (30F, 30R), a first solenoid switching valve (32), first shuttle valves (33F, 33R), and a controller 37. A second solenoid switching valve (34F) and a pressure sensor (35F) are provided in the front second line (28), and a second solenoid switching valve (34R) and a pressure sensor (35R) are provided in the rear second line (29). In a case where it is determined that each of the second brake valve (30F, 30R) is not performing normally based upon a pressure of a hydraulic fluid detected by each of the pressure sensors (35F, 35R) and an operating signal supplied to the first solenoid switching valve (32) or each of the second brake valves (30F, 30R), a controller 37 performs control to switch each of the second solenoid switching valves (34F, 34R).

公开(公告)号：US20180355583A1

公开(公告)日：2018-12-13

申请号：US15780313

申请日：2016-12-01

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Hidekazu MORIKI ,  Ryu NARIKAWA ,  Hiroaki TANAKA ,  Hiroshi SAKAMOTO ,  Yasutaka TSURUGA

IPC: E02F9/22 ,  E02F9/20 ,  E02F3/43

CPC classification number: E02F9/2235 ,  E02F3/43 ,  E02F9/20 ,  E02F9/2012

Abstract: The control system for the hydraulic construction machine includes: a hydraulic actuator; a work device driven by the hydraulic actuator; a hydraulic pump supplying a hydraulic fluid to the hydraulic actuator; a pump flow rate control section controlling the delivery flow rate of the hydraulic pump; a pump horsepower control section controlling the horsepower of the hydraulic pump; and a target surface distance acquiring section measuring or computing a target surface distance that is the distance between a construction target surface on which the work device works and the work device. The pump flow rate control section is configured to perform control such that as the target surface distance decreases, the delivery flow rate decreases, and the pump horsepower control section is configured to perform control such that as the target surface distance decreases, the horsepower of the hydraulic pump increases.

公开(公告)号：US20180119386A1

公开(公告)日：2018-05-03

申请号：US15567723

申请日：2016-02-23

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Hiroyuki KOBAYASHI ,  Hiroshi SAKAMOTO ,  Yoshiyuki TSUCHIE ,  Hidekazu MORIKI ,  Yasutaka TSURUGA

IPC: E02F9/20 ,  E02F3/32 ,  E02F9/22

CPC classification number: E02F9/2025 ,  E02F3/32 ,  E02F9/2004 ,  E02F9/2037 ,  E02F9/22 ,  E02F9/2285 ,  F15B11/08

Abstract: At times of a travel-solo state of the machine body, the outputting of unnecessary electric lever operating device signals caused by machine body oscillation due to the traveling is inhibited. At times of traveling work, the output limitation of electric lever operating device signals necessary for work is inhibited. 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. The dead zone calculation part sets the dead zone for the electric signal at a first predetermined value when the machine body is in the travel-solo state and sets the dead zone for the electric signal at a second predetermined value smaller than the first predetermined value when the machine body is in the traveling work state.

公开(公告)号：US20180073525A1

公开(公告)日：2018-03-15

申请号：US15563631

申请日：2015-04-03

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Tsutomu UDAGAWA ,  Hiroaki TANAKA ,  Yasutaka TSURUGA ,  Kazunori NAKAMURA

IPC: F15B11/17 ,  E02F9/22 ,  F15B11/02

CPC classification number: F15B11/17 ,  E02F9/2221 ,  E02F9/2235 ,  E02F9/2242 ,  E02F9/2292 ,  E02F9/2296 ,  F15B11/02 ,  F15B2211/20576 ,  F15B2211/2654 ,  F15B2211/30595 ,  F15B2211/6346 ,  F15B2211/6652 ,  F15B2211/6654 ,  F15B2211/7142 ,  F15B2211/75

Abstract: To provide a hydraulic control system for a working machine with high fuel efficiency and higher versatility to be capable of being adapted to special work. The hydraulic control system for the working machine according to the present invention includes: a plurality of directional control valves (31, 32, . . . ), more than one of which is connected in parallel to each of a plurality of hydraulic pumps (11, 12, 13) to supply hydraulic oil from the hydraulic pump to each of the corresponding actuators (4, 5, 6, 50); operating devices (110, 120, 130, 140) to which an operator inputs manipulated variables; a connection map (182) storing a precedence order for connection between a plurality of hydraulic pumps and a plurality of directional control valves; and a controller (100) controlling the connection conditions of the pumps and the actuators on the basis of the connection a¥map and operation signals.