公开(公告)号：EP4039886A1

公开(公告)日：2022-08-10

申请号：EP20872650.5

申请日：2020-09-08

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： IGARASHI, Teruki ,  NARAZAKI, Akihiro ,  MEGURIYA, Shuuichi

IPC: E02F3/43 ,  E02F9/20

Abstract: A work machine includes a work device having a boom, an arm, and work equipment and a controller that sets a target surface, and calculates a work equipment-to-target surface distance on the basis of signals from a position sensor and a posture sensor, and controls the boom and carries out deceleration control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when operation of the arm is carried out and the work equipment-target surface distance has become shorter than a predetermined distance. The controller determines whether or not there is a possibility that the work equipment enters the target surface when operation of the arm is carried out based on the set target surface and the signals from the position sensor and the posture sensor, and does not carry out the deceleration control even when the work equipment-to-target surface distance is shorter than the predetermined distance in the case in which it is determined that there is no possibility that the work equipment enters the target surface.

公开(公告)号：EP2101065A1

公开(公告)日：2009-09-16

申请号：EP07806966.3

申请日：2007-09-07

Applicant: Hitachi Construction Machinery Co., Ltd

Inventor： NAKAMURA, Kazunori ,  ISHIKAWA, Kouji ,  ARIGA, Nobuei ,  NARAZAKI, Akihiro

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

CPC classification number: F15B11/17 ,  E02F9/2235 ,  E02F9/2285 ,  E02F9/2292 ,  E02F9/2296 ,  F15B2211/20553 ,  F15B2211/20576 ,  F15B2211/26 ,  F15B2211/265

Abstract: The present invention provides a torque control apparatus for a construction machine three-pump system that can accurately control the total absorption torque of first, second, and third hydraulic pumps (2, 3, 4) and effectively use the output torque of an engine. A pump base torque computation section 42 calculates a pump base torque Tr from a target rotation speed. A subtraction section 44 calculates a reference value Tf for the maximum absorption torque available to the first and second hydraulic pumps 2, 3 by subtracting a third pump reference absorption torque T3r from the pump base torque Tr. A correction torque computation section 45 calculates a correction torque value from the delivery pressure of the third hydraulic pump 4. An addition section 46 calculates a target absorption torque Tn by adding the correction torque value Tm to the reference value Tf. A first regulator 31 is controlled so as to obtain the target absorption torque Tn.

公开(公告)号：EP4293236A1

公开(公告)日：2023-12-20

申请号：EP21931579.3

申请日：2021-03-18

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： AMANO, Hiroaki ,  KUMAGAI, Kento ,  OOHIRA, Hiroto ,  NISHIKAWA, Shinji ,  NARAZAKI, Akihiro ,  KODAKA, Katsuaki

IPC: F15B11/042

Abstract: A work machine includes: a main circuit that supplies a working fluid from a pump to an actuator; a pilot circuit that introduces part of the working fluid from the pump, to a pilot pressure receiving section of a control valve; a bleed-off passage that connects the pump and a tank. The pilot circuit is provided with: a first pressure reducing valve that generates a pilot primary pressure; and second and third pressure reducing valves that generate a pilot secondary pressure to be applied to the control valve and a bleed-off valve. A moving area of a spool of the bleed-off valve has a first moving area where an opening area of a restrictor changes stepwise, and a second moving area where the opening area of the restrictor changes continuously. A controller controls the third pressure reducing valve such that the spool is positioned in the first moving area at the time of non-operation of the actuator, and the spool is positioned in the second moving area at the time of operation of the actuator. The restrictor of the bleed-off valve has a restricting hole that gives a resistance to the working fluid passing therethrough in a case the spool is positioned in the first moving area.

公开(公告)号：EP4039892A1

公开(公告)日：2022-08-10

申请号：EP20871610.0

申请日：2020-09-29

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： AKITA, Tarou ,  KOBAYASHI, Takahiro ,  NARAZAKI, Akihiro ,  ITO, Masamichi

IPC: E02F9/22

Abstract: When an operation amount of an operation lever 1a or 1b corresponding to a boom cylinder 5 is equal to or smaller than an operation amount of an operation lever 1a or 1b corresponding to an arm cylinder 6, an estimated velocity of the arm cylinder used for region limiting control is computed on the basis of a first condition defining, in advance, a relation between the operation amount of the operation lever 1a or 1b and the estimated velocity of the arm cylinder 6. When the operation amount of the operation lever 1a or 1b corresponding to the boom cylinder 5 is larger than the operation amount of the operation lever 1a or 1b corresponding to the arm cylinder 6, the estimated velocity of the arm cylinder 6 used for the region limiting control is computed as a velocity higher than the estimated velocity of the arm cylinder 6 computed on the basis of the first condition. The behavior of a work device can thereby be stabilized.

公开(公告)号：EP4012113A1

公开(公告)日：2022-06-15

申请号：EP21779716.6

申请日：2021-03-18

Applicant: Hitachi Construction Machinery Co., Ltd.

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

IPC: E02F9/20 ,  F15B11/024 ,  F15B11/042 ,  F15B11/08

Abstract: Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

公开(公告)号：EP4012108A1

公开(公告)日：2022-06-15

申请号：EP20927965.2

申请日：2020-11-02

Applicant: Hitachi Construction Machinery Co., Ltd.

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

IPC: E02F3/43 ,  E02F9/22 ,  E02F9/26 ,  F15B11/044

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：EP3951070A1

公开(公告)日：2022-02-09

申请号：EP19921239.0

申请日：2019-11-29

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： ITOH, Masamichi ,  IGARASHI, Teruki ,  NARAZAKI, Akihiro

IPC: E02F3/43

Abstract: When a bucket 10 is grounded on soil, an operation signal is outputted or corrected such that a relative angle of the bucket 10 with respect to a target surface is maintained if a distance D between the bucket 10 and the target surface 60 is equal to or less than a preset first threshold value D1. When the bucket 10 is not grounded on soil, the operation signal is outputted or corrected such that the relative angle of the bucket 10 with respect to the target surface 60 is maintained if the distance between the bucket 10 and the target surface 60 is equal to or less than a preset second threshold value D2 set smaller than the first threshold value D1. As a result, control to maintain an angle of a work tool can be suitably started.

公开(公告)号：EP3492664A1

公开(公告)日：2019-06-05

申请号：EP18763475.3

申请日：2018-02-21

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： KANETA, Tomoaki ,  NARAZAKI, Akihiro ,  KODAKA, Katsuaki

IPC: E02F9/22

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. A hydraulic excavator 1 with a front mechanism including an arm 33 driven by a hydraulic actuator 43 through operation of an operating lever 50 includes: first and second angle sensors 37 and 38 which detect the posture of the arm 33; and a controller 49 which, when the posture of the arm 33 is at a remoter side from an upperstructure 20 than a preset position and the position of a bucket 35 is adjusted from a maximum or nearly maximum preset operation amount of the operating lever 50 in arm pushing operation by the operating lever 50, changes the flow rate characteristic of pressure oil in relation to discharge pressure of a hydraulic pump 41 for supplying pressure oil to the hydraulic actuator 43, to characteristic PTS with a higher flow rate than flow rate characteristic PT at the time of operation with an operation amount other than the above operation amount, to drive the hydraulic pump 41.

公开(公告)号：EP4230805A1

公开(公告)日：2023-08-23

申请号：EP21882697.2

申请日：2021-10-14

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： MEGURIYA, Shuuichi ,  IGARASHI, Teruki ,  NARAZAKI, Akihiro

IPC: E02F3/43 ,  E02F9/20 ,  E02F9/26

Abstract: A work machine includes: a swing structure; a work device; a position sensor that senses position information of the swing structure; a posture sensor that senses information about the posture of the work machine; and a controller that performs machine control on the basis of a target surface set on the basis of target shape data, the position information of the swing structure, and the information about the posture of the work machine. When the controller becomes unable to obtain the position information of the swing structure by the position sensor, the controller stores, as reference swing angle information, swing angle information of the swing structure, the swing angle information being sensed by the posture sensor at that time. The controller prohibits execution of the machine control when the swing structure is positioned outside a swing range set on the basis of the reference swing angle information. The controller permits the execution of the machine control when the swing structure is positioned inside the swing range and when the swing structure is positioned inside the swing range again after being positioned outside the swing range.

公开(公告)号：EP4015714A1

公开(公告)日：2022-06-22

申请号：EP20907891.4

申请日：2020-12-10

Applicant: Hitachi Construction Machinery Co., Ltd.

Inventor： KAMEOKA, Ryota ,  NISHIKAWA, Shinji ,  NARAZAKI, Akihiro

IPC: E02F9/20 ,  E02F9/24 ,  E02F9/26

Abstract: It is contrived to achieve both a control for limiting operation of a machine body and a control for raising engine speed when an obstacle is detected. To this end, a machine controller 13 performs operation limiting control by conducting a control for reducing the speed of the engine 19 when the machine body does not require engine speed increase control and no obstacle is sensed by obstacle sensors 5 to 8, and the machine controller 13 performs supply flow rate reduction control for reducing the flow rates of the hydraulic fluid supplied to hydraulic actuators 3d to 3h from a hydraulic pump 21 when the machine body requires the engine speed increase control and an obstacle is sensed by the obstacle sensors 5 to 8.