Hitachi Construction Machinery Co., Ltd.

Kabushiki Kaisha Toyota Jidoshokki

Kcm Corporation

Kouji Ishikawa

Shinya Imura

Hidetoshi Satake

Seiji Hijikata

Tsuyoshi Nakamura

Takatoshi Ooki

Shinji Nishikawa

Shiho Izumi

Kazunori Nakamura

Genroku Sugiyama

Manabu Edamura

Tsukasa Toyooka

Toichi Hirata

Masatoshi Hoshino

Yasuo Okano

Tomoaki Kaneta

Yusuke Kajita

Hideo Karasawa

Kensuke Sato

Nobuei Ariga

Hidekazu Moriki

Hiroaki Amano

Yoichi Kowatari

Youichi Kowatari

Ryohei Yamashita

Kiwamu Takahashi

Yasushi Arai

Yasutaka Tsuruga

Hiroyuki Azuma

Takenori Hiroki

Naoki Hagiwara

Shuuichi Meguriya

Keiichiro Nakamura

Tarou Akita

Ryuu Narikawa

Shinya Sato

Shinji Ishihara

Hidenobu Tsukada

Shohei Kamiya

Kouichi Shibata

Yasunori Ota

Eitaro Ito

Mitsuhiko Kanehama

Tadatoshi Shimamura

Kentarou Itoga

Manabu Sugiura

Shigehiro Yoshinaga

Ken Imamura

Seiji Ishida

Akihiro Narazaki

Ei Takahashi

Toshihiro Abe

Tsutomu Udagawa

Daisuke Nogami

Tomoki Kimura

Yuichi Ogawa

Junko Suzuki

Hiroki Takeuchi

Daito Sakai

Masanori Ezawa

Hiroshi Sakamoto

Kenji Hiraku

Ryu Narikawa

Kazuhiro Shibamori

Yasuhiko Kanari

Yuuki Gotou

Toshihiko Ishida

Mitsugu Ojima

Akira Nakayama

Toshihiko Watanabe

Shinya Okumura

Tsutomu Umehara

Yuuichirou Morita

Takahiko Kurose

Motoyuki Yabuuchi

Masao Nishimura

Hidefumi Takegahara

Nobuo Uzawa

Satoshi Iwasaki

Yuusuke Kajita

Naoki Ishikawa

Yasuharu Gotou

Shigetoshi Konno

Shingo Sawada

Tsuyoshi Hitachi Kenki Tsukubaryo Nakamura

Masao Hitachi Kenki Tsukubaryo Nishimura

A work machine () having a controller () that can perform area limiting control, the work machine further includes a machine control ON/OFF switch () that alternatively selects an ON position permitting execution of the area limiting control and an OFF position prohibiting execution of the area limiting control. The controller () has an engine control section () that performs automatic idling control when a predetermined period of time (T1) has elapsed after a point in time when all of operation levers () have attained a neutral state. The engine control section () is configured to execute the automatic idling control during when the switch () is in the OFF position and not to execute the automatic idling control during when the switch () is in the ON position.

Hydraulic excavator with area limiting control function

A hydraulic excavator includes a controller () that executes region limiting control to forcibly raise a boom () in such a manner that a position of a tip end of a bucket () is kept on a target excavation surface and within a region above the target excavation surface if an operation device () issues an action direction to an arm () or the bucket. The controller determines which is selected as a control mode over a raising speed of the boom at a time of executing region limiting control, a first mode or a second mode specified by a raising speed lower than a raising speed of the first mode if the tip end of the bucket is located below the target excavation surface, and controls the raising speed of the boom based on a result of determination.

Hydraulic excavator

A first torque control proportional electromagnetic valve () is connected through a first torque control line () to a third pressure receiving chamber (D) in a first torque control regulator (). A second torque control proportional electromagnetic valve () is connected through a second torque control line () to a third pressure receiving chamber (D) in a second torque control regulator (). The first and second torque control proportional electromagnetic valves () are controlled by a controller. A switching valve () is provided between the first torque control line () and the second torque control line (). The switching valve () supplies an output pressure of the first torque control proportional electromagnetic valve () to the third pressure receiving chamber (D) in the second torque control regulator () at the time of driving hydraulic motors (B,C) for left side and right side traveling.

Hydraulic drive apparatus

A controller () is provided with an elapse time measuring section (A) that measures an elapse time (tx) elapsed since an initial use of an accumulator () based upon a reset signal from a reset switch (), a number-of-operations measuring section (B) that measures a number of operations of the accumulator (), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (), a gas permeation amount estimating section (C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (), a sealed gas pressure estimating section (D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (B) of the accumulator (), and an accumulator degradation determining section (E) that determines a degradation condition of the accumulator () and outputs the determination result.

Hydraulic energy recovery apparatus for working machine

A work machine includes: control valves that control flows of a hydraulic operating oil supplied to actuators; operation lever devices that generate hydraulic signals to be output to the corresponding control valves according to an operation; solenoid proportional valves that reduce pressure of the hydraulic signals generated by the corresponding operation lever devices; and a front implement control section that controls the solenoid proportional valves. The work machine further includes: operation signal lines connected to the operation lever devices; signal input lines connected to the control valves; pressure reducing lines provided with the solenoid proportional valves; and selector valves that have a first position that interrupts connection of the operation signal lines and the pressure reducing lines and directly connects the operation signal lines to the signal input lines, and a second position that connects the operation signal lines to the signal input lines via the pressure reducing lines.

Work machine

A hydraulic circuit () of a hydraulic excavator () is provided with a main hydraulic circuit (A) including a boom cylinder (D), a pilot hydraulic circuit (B) for operating the boom cylinder (D) and a recovery hydraulic circuit (C) including an accumulator (). In this case, the recovery hydraulic circuit (C) is provided with a recovery control valve () that recovers pressurized oil discharged from the boom cylinder (D) to the accumulator (), a main supply control valve () for supplying pressurized oil accumulated in the accumulator () to the main hydraulic circuit (A) and a pilot supply control valve () for supplying pressurized oil accumulated in the accumulator () to the pilot hydraulic circuit (B).

Construction machine

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.

Hydraulic drive system

A work machine including a front control section configured to calculate a limit command value for restricting an operation of a front work implement includes: for example, a bypass line that bypasses, for example, the proportional solenoid valve in, for example, the pilot line; for example, a bypass valve disposed in, for example, the bypass line; a switch configured to output a signal to turn on or off control by the front control section; an on/off determining part configured to determine whether the signal from the switch is an on signal that brings front control into an on state or an off signal that brings the front control into an off state; an open/close command part configured to generate an open/close command signal to open the bypass valve when the signal is determined to be the off/off signal.

Provided is a work machine that is equipped with a control unit that executes area limiting control with respect to a work device. The control unit includes: a position computing section that calculates the position, on an operation plane, of the forward end (first reference point) of a bucket and the rear end (second reference point) of the bucket; and a first distance computing section that calculates the distances in the operating plane from the first reference point and the second reference point to the target face A to be controlled. When the smaller one of the two distances is equal to or lower than a threshold during area limiting control, the control unit corrects an operation signal output from an operation lever device so as to reduce the operating speed of a hydraulic actuator that is a control target of the operation signal.

A work machine including: a hydraulic cylinderconfigured to drive a work implement; a control valveconfigured to connect a delivery line of a hydraulic pumpswitchingly to a bottom fluid chamber and a rod fluid chamber of the hydraulic cylinderand a tank; a pilot pumpconfigured to output a pilot pressure to drive the control valve; an engineconfigured to drive the hydraulic pumpand the pilot pump; and an accumulatorconfigured to accumulate a return hydraulic fluid from the hydraulic cylinderis provided with: a bypass lineconfigured to connect the bottom fluid chamber of the hydraulic cylinderand a delivery lineof the hydraulic pumpby bypassing the control valveand be provided with the accumulatorthereon; a pressure-accumulation control valveprovided between the bottom fluid chamber of the hydraulic cylinderand the accumulator; a release control valveprovided between the accumulatorand the delivery line; and a hydraulic system controllerconfigured to open the release control valveif an engine revolution speed N becomes lower than a set value Ns.

A hydraulic excavator () includes a controller () for generating, when the tip of a work implement (A) is approaching a target surface () due to the pilot pressure output from an operating device (), a control signal for a boom cylinder () such that the tip of the work implement moves along the target surface and controlling the work implement (A) by outputting the generated control signal to the flow control valve () of the boom cylinder (). The controller calculates the positional information of a finished shape () formed by the work implement, based on the topographic information input from a topographic measurement device () that measures the topography near the work machine and corrects the control signal based on the positional information of the finished shape such that the finished shape gets closer to the target surface.

A work machine includes: a multi-joint type work implement; a plurality of hydraulic actuators driving the work implement; an operation device outputting an operation signal to the plurality of hydraulic actuators; a storage section storing a target configuration defined by connecting a plurality of target surfaces; a control object surface selection section that in the case where a control point set at a claw tip of a bucket is under the target configuration, uses a target surface closest to the control point on the target configuration as a control object surface; and a target operation control section that controls the plurality of hydraulic actuators such that the operational range of the control point is limited to the control object surface and a region above the same in the case where an excavation operation is input from an operator via the operation device.

An area limit control part as a control section outputs a requested boost pilot pressure for driving a control valve, based upon a pilot pressure in accordance with an operating amount of an operating lever and a posture signal of a posture sensor. A drive permission determination part determines whether or not a drive of a hydraulic actuator is permitted based upon the pilot pressure in accordance with the operating amount of the operating lever. A pilot pressure selecting part selects the requested boost pilot pressure from the area limit control part in such a manner as to drive the control valve with the requested boost pilot pressure to the hydraulic actuator the drive of which is permitted, and not to drive the control valve to the hydraulic actuator the drive of which is not permitted.

Drive control device for construction machine

Provided is a work machine capable of regenerating a return hydraulic fluid from a hydraulic actuator while preventing a drag loss of a regeneration hydraulic motor and a hydraulic pump from increasing and preventing the regeneration efficiency of the regeneration hydraulic motor from decreasing. A controllercomputes a required regeneration hydraulic motor revolution speed from a displacement of a regeneration hydraulic motorand a regeneration flow rate of the regeneration hydraulic motor, computes a required first hydraulic pump revolution speed from a displacement of a first hydraulic pumpand a target assist flow rate of the first hydraulic pump, and selects a greater one of the required regeneration hydraulic motor revolution speed and the required first hydraulic pump revolution speed as a target revolution speed of an electric motor

A work machine has a controller which has an area limiting control section correcting the pilot pressures of pilot lines, a regeneration control section adjusting the flow rate of the hydraulic fluid caused to flow from a tank side line of an arm cylinder into a pump side line thereof between zero and a predetermined upper limit value, and a regeneration control switching section that issues an order to the regeneration control section to set the predetermined upper limit value to a first set value when the function of the area limiting control section is invalid and that issues an order to the regeneration control section to set the predetermined upper limit value to a second set value that is smaller than the first set value when the function of the area limiting control section is effective.

Growing community of inventors

Kasumigaura, Japan

Kouji Ishikawa