公开(公告)号：EP3369867B1

公开(公告)日：2020-11-11

申请号：EP17209816.2

申请日：2017-12-21

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： TAKAHASHI, Hiromasa ,  HIRAKU, Kenji ,  SHIMIZU, Juri ,  SUGIKI, Shohei

IPC: E02F9/22

公开(公告)号：EP3744988A1

公开(公告)日：2020-12-02

申请号：EP19845986.9

申请日：2019-08-05

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： TAKIMOTO, Yoshifumi ,  TAKIGUCHI, Kazuo ,  IIO, Chinori ,  OKAMURA, Jun ,  TAKAHASHI, Hiromasa

IPC: F15B20/00 ,  E02F9/22 ,  F15B11/02

Abstract: There is provided a hydraulic drive device for a working machine with which a number of times of maintenance can be reduced. A controller (20) opens a first on-off valve (25a), closes a second on-off valve (25b), switches a first directional switching valve (30a) to a first position (A), and switches a second directional switching valve (30b) to a third position (C), thereby pressure oil from a hydraulic pump (1a) is supplied from the first on-off valve to an actuator (5a) through the first directional switching valve. When history data of the first on-off valve is determined to satisfy a prescribed condition, the controller closes the first on-off valve, opens the second on-off valve, switches the first directional switching valve to a second position (B), and switches the second directional switching valve to a fourth position (D), thereby pressure oil from the hydraulic pump is supplied from the second on-off valve to the actuator through the second directional switching valve. For example, the controller determines that the prescribed condition is satisfied when an operation number of times of the first on-off valve reaches a first prescribed value.

公开(公告)号：EP3683453A1

公开(公告)日：2020-07-22

申请号：EP18856734.1

申请日：2018-04-06

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SHIMIZU, Juri ,  HIRAKU, Kenji ,  TAKAHASHI, Hiromasa ,  SUGIKI, Shohei

IPC: F15B11/08 ,  E02F9/22 ,  F15B11/02 ,  F15B11/028 ,  F15B11/044

Abstract: Provided is a work machine that can selectively establish a closed circuit connection between a single rod-type hydraulic cylinder and a plurality of bidirectional-type hydraulic pumps, the work machine being capable of enhancing responsiveness of the single rod-type hydraulic cylinder when a high-speed lever switching operation is conducted in a state in which a rod pressure of the single rod-type hydraulic cylinder is higher than a bottom pressure.
When a bucket lever (70a) is operated to a side of extending the bucket cylinder in a state in which a pressure in a rod chamber (5b) of the bucket cylinder (5) is higher than a pressure in a bottom chamber (5a), a controller (50) opens a rod-side proportional valve (45) and discharges a working fluid in the rod chamber to a working fluid tank (25) such that a differential pressure between the pressure in the rod chamber and the pressure in the bottom chamber is reduced below a switching pressure (Psw) of a flushing valve (33) .

公开(公告)号：EP3835598A1

公开(公告)日：2021-06-16

申请号：EP19911321.8

申请日：2019-11-05

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SAITOH, Teppei ,  TAKAHASHI, Hiromasa ,  HIRAKU Kenji

IPC: F15B11/08 ,  F15B11/17

Abstract: Provided is a construction machine on which a hydraulic closed circuit for driving a single rod-type hydraulic cylinder and a swing hydraulic motor is mounted and that has good swing deceleration responsiveness. In this construction machine that drives each of a single rod-type hydraulic cylinder and a swing hydraulic motor in a closed circuit, a minimum passage area from a second flushing valve to a tank in a case the second flushing valve is fully open is smaller than a minimum passage area from a first flushing valve to the tank in a case the first flushing valve is fully open.

公开(公告)号：EP3369867A1

公开(公告)日：2018-09-05

申请号：EP17209816.2

申请日：2017-12-21

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： TAKAHASHI, Hiromasa ,  HIRAKU, Kenji ,  SHIMIZU, Juri ,  SUGIKI, Shohei

IPC: E02F9/22

Abstract: A drive system for a construction machine capable of appropriately controlling a distribution flow rate to each hydraulic actuator and improving operability by an operator is provided. A flow rate distribution section 32 that computes a distribution flow rate of a hydraulic fluid supplied to each of a plurality of hydraulic actuators 4-7 on the basis of a demanded flow rate, sets, within a distributable region set for computing a range of a distributable flow rate that is a flow rate of the hydraulic fluid suppliable to each of at least two hydraulic actuators driven by a combined operation among the plurality of hydraulic actuators 4-7 from a plurality of hydraulic pump devices 10a-10d for the at least two hydraulic actuators, a distribution region for computing a range of the distribution flow rate of the hydraulic fluid actually supplied to each of the at least two hydraulic actuators, and computes the distribution flow rate in such a manner that the distribution flow rate falls within the distribution region and a ratio among the distribution flow rates of the plurality of hydraulic actuators 4-7 is equal to a ratio among the demanded flow rates of the plurality of hydraulic actuators 4-7.

公开(公告)号：EP4001666A1

公开(公告)日：2022-05-25

申请号：EP20858546.3

申请日：2020-08-25

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SUGIKI, Shohei ,  HIRAKU, Kenji ,  TAKAHASHI, Hiromasa ,  SAITOH, Teppei ,  SHIMIZU, Juri

IPC: F15B11/02 ,  E02F9/22 ,  F15B11/08

Abstract: Provided is a construction machine in which travel operability is not impaired when a combined operation is performed in which a single-rod hydraulic cylinder is driven during a travel operation. A hydraulic excavator includes a controller that controls the delivery direction and delivery flow rate of a closed-circuit pump, opens and closes a travel switching valve and an assist switching valve, and controls the delivery flow rate of the open-circuit pump, according to a travel operation lever and a work operation lever. The controller holds the assist switching valve in a closed position irrespective of whether or not the work operation lever is operated in a case where the travel operation lever is operated.

公开(公告)号：EP3779210A1

公开(公告)日：2021-02-17

申请号：EP19825561.4

申请日：2019-05-20

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SHIMIZU, Juri ,  HIRAKU, Kenji ,  TAKAHASHI, Hiromasa ,  SAITOU, Teppei ,  SUGIKI, Shouhei

IPC: F15B11/02 ,  E02F9/22 ,  F15B11/028 ,  F15B11/17

Abstract: An object of the present invention is to provide a construction machine capable of suppressing lugging down of an engine irrespective of contents of operation of an operator and the load state of a hydraulic actuator. A controller 50 includes: a demanded torque estimating section 50c configured to estimate demanded torque as torque demanded from an engine 9 by the first hydraulic pump on the basis of a demanded velocity of a first hydraulic actuator 1 and a load pressure on the first hydraulic actuator; a demanded velocity limiting section 50d configured to, in a case in which a demanded torque change rate as a change rate of the demanded torque exceeds a predetermined change rate, limit the demanded velocity such that the demanded torque change rate becomes equal to or lower than the predetermined change rate; and a command calculating section 50e configured to calculate a delivery flow rate of the first hydraulic pump on the basis of the demanded velocity of the first hydraulic actuator, the demanded velocity being limited by the demanded velocity limiting section.

公开(公告)号：EP3742000A1

公开(公告)日：2020-11-25

申请号：EP18901447.5

申请日：2018-01-16

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： TAKAHASHI, Hiromasa ,  SUGIKI, Shohei ,  HIRAKU, Kenji ,  SHIMIZU, Juri ,  SAITOH, Teppei

IPC: F15B11/02 ,  F15B11/08 ,  E02F9/22

Abstract: A construction machine is provided which includes a hydraulic closed circuit in which a single rod hydraulic cylinder is driven directly by a bidirectionally tiltable variable displacement pump and can stably speed up the contraction action of the single rod hydraulic cylinder.
In the case where a contraction action of a hydraulic cylinder 10 is instructed through an operation lever 30, when a differential pressure obtained by subtracting the pressure of a cap chamber 10a from the pressure of a rod chamber 10b is equal to or lower than a first threshold value α set to a level equal to or higher than a selection setting pressure of a flushing valve 14, a controller 20 closes a rod side selector valve 12b to disable rod assist action for supplying hydraulic fluid from a second hydraulic pump 8 to the rod chamber, and when the differential pressure is higher than the first threshold value, the controller 20 opens the rod side selector valve to enable the rod assist action.

公开(公告)号：EP3604824A1

公开(公告)日：2020-02-05

申请号：EP18774535.1

申请日：2018-02-06

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SAITOH, Teppei ,  KAI, Takamasa ,  HIRAKU, Kenji ,  TAKAHASHI, Hiromasa ,  SHIMIZU, Juri

IPC: F15B20/00 ,  E02F9/20 ,  E02F9/22 ,  F15B11/02 ,  F15B11/028 ,  F15B11/08 ,  F15B11/17

Abstract: [Subject] To provide a construction machine that incorporates a hydraulic closed circuit system capable of suppressing, even where a selector valve is sticked in an open state by a failure of the selector valve or a control system therefor, unintended operation of a hydraulic actuator and continuing operation of a machine body.
[Solving Means] The construction machine includes first sensors (37d to 40d) that detect open-closed states of a plurality of switching valves (37 to 40), first compulsory valve closing devices (50, 51) that change over the plurality of switching valves to a closed position irrespective of open-close control by a machine body controller (11), and a valve device controller (33) that controls, when it is detected based on the open-closed states of the plurality of selector values detected by the first sensors that one of the plurality of selector values is sticked in an open state, the first compulsory valve closing device such that other selector valve connected to one of the plurality of closed circuit pumps (35, 36) to which the one selector valve is connected is closed.

公开(公告)号：EP3546662A1

公开(公告)日：2019-10-02

申请号：EP17873730.0

申请日：2017-11-16

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： SAITOH, Teppei ,  HIRAKU, Kenji ,  SHIMIZU, Juri ,  TAKAHASHI, Hiromasa

IPC: E02F9/22 ,  F15B20/00

Abstract: This construction machine includes a first hydraulic drive device that is driven by a first prime mover and a second hydraulic drive device that is driven by a second prime mover. The first hydraulic drive device has a first closed circuit that connects a first hydraulic actuator and a first closed-circuit pump and a first assist flow path that connects the first closed circuit and a first open-circuit pump and that supplies pressure oil from the first open-circuit pump to the first closed circuit. The second hydraulic drive device is provided with a second closed circuit that connects a second hydraulic actuator and a second closed-circuit pump. The present invention also includes a first emergency flow path that branches from the first assist flow path and connects to the second closed circuit and that supplies pressure oil from the first open-circuit pump to the second closed circuit.