公开(公告)号：US20240352710A1

公开(公告)日：2024-10-24

申请号：US18685547

申请日：2022-10-31

Applicant: Hitachi Construction Machinery Co., Ltd.

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

IPC: E02F9/22

CPC classification number: E02F9/2217 ,  E02F9/2225 ,  E02F9/2285

Abstract: An object of the present invention is to provide a work machine that makes it possible to perform, with a simple configuration, speed control of respective actuators and thrust control of a particular actuator that regenerates the flow of a return fluid, at the time of combined operation to simultaneously drive the particular actuator and another actuator. For this purpose, a controller calculates a target thrust that is a target value of a thrust of the particular actuator on the basis of an input amount of an operation device and an output value of a posture sensor, calculates a target meter-out pressure that is a target value of a meter-out pressure of the particular actuator on the basis of the target thrust and a meter-in pressure of the particular actuator, and calculates a regeneration control valve target opening area that is a target value of an opening area of a regeneration control valve on the basis of the target meter-out pressure and the meter-out pressure of the particular actuator.

公开(公告)号：US20240068203A1

公开(公告)日：2024-02-29

申请号：US18272121

申请日：2022-01-19

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Masatoshi HOSHINO ,  Ryou YAGISAWA

IPC: E02F9/22 ,  E02F9/12

CPC classification number: E02F9/2217 ,  E02F9/123

Abstract: A work machine includes a hydraulic pump that is driven by an engine and delivers a pressurized fluid, a hydraulic actuator that is operated by the pressurized fluid delivered by the hydraulic pump, a hydraulic accumulator device that accumulates the pressurized fluid discharged from the hydraulic actuator, a differential pressure control valve that is disposed between the hydraulic actuator and the hydraulic accumulator device and generates a differential pressure across the differential pressure control valve between a pressure of the hydraulic actuator and a pressure of the hydraulic accumulator device, a pressure sensor that senses the pressure of the hydraulic accumulator device, and a controller that controls the differential pressure control valve on the basis of a sensing result of the pressure sensor. The controller controls the differential pressure control valve in such a manner that the differential pressure across the differential pressure control valve reduces according to a rise in the pressure of the hydraulic accumulator device sensed by the pressure sensor.

公开(公告)号：US20230358022A1

公开(公告)日：2023-11-09

申请号：US18025707

申请日：2021-12-08

Applicant: Hitachi Construction Machinery Co., Ltd.

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

IPC: E02F9/22

CPC classification number: E02F9/2228

Abstract: The invention of the present application intends to provide a work machine that can ensure high operability by preventing abrupt actuation of an actuator and a shock to a machine body by use of a bleed-off function at the time of starting of the actuator and that can improve the energy-saving performance by reducing a bleed-off flow rate after the starting of the actuator. For this purpose, a controller opens a bleed-off valve at a timing at which an operation device is being operated and before a flow rate of a hydraulic pump starts increasing, and closes the bleed-off valve at a timing at which the operation device is being operated and after the flow rate of the hydraulic pump has started increasing.

公开(公告)号：US20230085676A1

公开(公告)日：2023-03-23

申请号：US17908956

申请日：2021-10-18

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Masatoshi HOSHINO ,  Ryou YAGISAWA

IPC: E02F9/22 ,  E02F9/20 ,  F15B1/04 ,  F15B13/02

Abstract: The present invention provides a construction machine equipped with a pressure accumulation device that accumulates return oil from an actuator, and that can implement both improvement in fuel efficiency with enhancement in workability. To achieve the foregoing, a controller sets an actuator upper limit output power that is an upper limit for an output power of the actuator according to a work mode selected by a work mode selection device, and controls a first control valve and a second control valve such that a sum of an output power of a hydraulic pump and an output power of the pressure accumulation device does not exceed the actuator upper limit output power.

公开(公告)号：US20230084767A1

公开(公告)日：2023-03-16

申请号：US17802745

申请日：2021-04-07

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Kenji HIRAKU ,  Masatoshi HOSHINO

IPC: E02F9/22 ,  F15B11/028 ,  F15B11/08

Abstract: It is an object of the present invention to provide a construction machine capable of efficiently driving a hydraulic cylinder by an accumulator. Thus, the construction machine includes a first control valve disposed in a first hydraulic fluid line connecting a bottom-side fluid chamber of a hydraulic cylinder with an accumulator, and a second control valve disposed in a second hydraulic fluid line connecting a rod-side fluid chamber of the hydraulic cylinder with a tank. The construction machine further includes a third control valve disposed in a third hydraulic fluid line connecting the rod-side fluid chamber with the accumulator, and a fourth control valve disposed in a fourth hydraulic fluid line connecting a line part of the first hydraulic fluid line, which connects the bottom-side fluid chamber with the third control valve, and a line part of the third hydraulic fluid line, which connects the rod-side fluid chamber with the third control valve, with each other.

公开(公告)号：US20220154741A1

公开(公告)日：2022-05-19

申请号：US17435602

申请日：2020-05-20

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Hiroki ISHII ,  Shinjiro YAMAMOTO ,  Masamichi ITOU ,  Yasutaka TSURUGA ,  Shinya IMURA

IPC: F15B15/20

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. A controller 40 switches the selector valves 203a and 203b to either one of a first position and a second position on the basis of signals from pressure sensors 70a and 70b and pressure sensors 200a and 200b and target operation set in advance regarding the selector valves 203a and 203b.

公开(公告)号：US20200232488A1

公开(公告)日：2020-07-23

申请号：US15755342

申请日：2016-09-29

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： Seiji HIJIKATA ,  Yasutaka TSURUGA ,  Kenji HIRAKU ,  Kouji ISHIKAWA

IPC: F15B21/14 ,  F15B1/02

Abstract: It is an object of the present invention to provide a hydraulic drive system that effectively utilizes a hydraulic fluid accumulated in an accumulator to make it possible to achieve a substantial improvement in terms of efficiency for a work machine as a whole. A hydraulic drive system includes: a first hydraulic pump; a first hydraulic actuator driven by being supplied with a hydraulic fluid from the first hydraulic pump; a first line for supplying the hydraulic fluid from the first hydraulic pump to the first hydraulic actuator; a first pump flow adjustment device installed in the first line, the first pump flow adjustment device being configured to adjust; a first hydraulic accumulator for accumulating the hydraulic fluid delivered from the first hydraulic pump; and a first accumulation flow adjustment device configured to adjust the flow of the hydraulic fluid from the first hydraulic pump to the first hydraulic accumulator. The hydraulic drive system further comprises a first accumulation flow supply device configured to supply the hydraulic fluid accumulated in the first hydraulic accumulator to the first hydraulic actuator via a second line different from the first line.

公开(公告)号：US20180347150A1

公开(公告)日：2018-12-06

申请号：US15778301

申请日：2016-11-11

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Hidekazu MORIKI ,  Hiroshi SAKAMOTO ,  Yasutaka TSURUGA ,  Tadashi OSAKA ,  Ryu NARIKAWA

IPC: E02F9/20 ,  E02F3/32 ,  E02F9/12 ,  E02F3/42 ,  E02F9/22 ,  E02F9/26 ,  E02F3/43 ,  F15B15/18 ,  F15B15/28

CPC classification number: E02F9/2033 ,  B66C13/18 ,  B66C23/82 ,  B66C23/86 ,  E02F3/32 ,  E02F3/425 ,  E02F3/435 ,  E02F9/123 ,  E02F9/2004 ,  E02F9/2225 ,  E02F9/2267 ,  E02F9/26 ,  F15B11/04 ,  F15B13/02 ,  F15B15/18 ,  F15B15/2815

Abstract: A control system for a construction machine stops an upper swing structure at a desired swing stop angle. A main controller sets a swing stop target angle at which an upper swing structure is to be stopped. A swing stoppability determination section reads an angle signal of the upper swing structure with respect to an undercarriage and an angle of a work implement, and determines whether the swing of the upper swing structure can be stopped at the swing stop target angle. A work implement is controlled in such a manner that an extension action of the work implement in a swing radial direction is prohibited or a contraction action of the work implement in the swing radial direction is executed in response to a signal that indicates whether the swing can be stopped and that is determined by the swing stoppability determination section.

公开(公告)号：US20180266083A1

公开(公告)日：2018-09-20

申请号：US15764425

申请日：2016-10-05

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

Inventor： Ryu NARIKAWA ,  Hidekazu MORIKI ,  Yasutaka TSURUGA ,  Hiroshi SAKAMOTO ,  Shiho IZUMI

IPC: E02F9/26 ,  E02F3/43 ,  E02F3/32 ,  E02F9/20 ,  E02F9/22 ,  E02F3/42 ,  F02D29/04

CPC classification number: E02F9/265 ,  E02F3/32 ,  E02F3/425 ,  E02F3/435 ,  E02F9/2033 ,  E02F9/2066 ,  E02F9/2232 ,  E02F9/2235 ,  E02F9/2296 ,  F02D29/00 ,  F02D29/04 ,  F02D2200/101

Abstract: A hydraulic excavator includes: a hydraulic pump driven by power generated by an engine; a work device that operates by a plurality of hydraulic cylinders driven by power generated by the hydraulic pump; an actuator control section that controls the boom cylinder in such a manner that a tip end of a bucket is located on or above a target surface; a control point position calculation section that calculates a bucket claw tip position on the basis of angle sensors; and a power generator control section that imposes more limitations on output power ranges of the engine and the hydraulic pump when a distance between the claw tip position and the target surface is equal to or smaller than a threshold D than those when the distance between the claw tip position and the target surface is larger than the threshold D.

公开(公告)号：US20180223500A1

公开(公告)日：2018-08-09

申请号：US15749828

申请日：2016-03-15

Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.

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

IPC: E02F3/43 ,  E02F9/22 ,  E02F9/20 ,  E02F3/32

Abstract: A construction machine includes a control device having a reaction-force correction control section. When a difference between a target operator input and an actual operator input for a front member exceeds a preset range, the reaction-force correction control section executes correction to increase an operation reaction force to be applied by a reaction-force applying device to an operating unit operating an actuator driving the front member. When the difference falls within the range, the reaction-force correction control section executes correction to decrease the operation reaction force to be applied by the reaction-force applying device to the operating unit operating the actuator driving the front member.