Hitachi Construction Machinery Co., Ltd.

Zexel Gmbh

Hitachi Construction Machinery

Genroku Sugiyama

Toichi Hirata

Hiroshi Watanabe

Tsukasa Toyooka

Hiroyuki Adachi

Koichi Shibata

Hideaki Tanaka

Kouji Ishikawa

Tsuyoshi Nakamura

Yusuke Kajita

Hideki Komatsu

Kazunori Nakamura

Shinya Imura

Yasutaka Tsuruga

Kento Kumagai

Takaaki Chiba

Hideo Karasawa

Masakazu Haga

Kazuhiro Shibamori

Youichi Kowatari

Osamu Tomikawa

Hiroshi Onoue

Shinji Nishikawa

Akihiro Narazaki

Hiroaki Amano

Masami Ochiai

Tadatoshi Shimamura

Shigehiro Yoshinaga

Kiyoshi Ono

Shinichi Satoh

Shuichi Miura

Katsuaki Kodaka

Yusaku Nozawa

Ei Takahashi

Shinjiro Yamamoto

Kuniaki Yoshida

Koji Ishikawa

Koji Mitsuya

Yoshiaki Saito

Atsushi Sato

Takatoshi Ooki

Eiki Izumi

Yoichi Kowatari

Hiroshi Ogura

Nobuei Ariga

Akira Tatsumi

Kentaro Itoga

Masao Kariya

Masaki Egashira

Rindo Morikawa

Wataru Idetsu

Yasushi Ochiai

Yasuo Tanaka

Yukio Aoyagi

Yuji Yoshitomi

Akihiko Yamamoto

Tsuyoshi Sakyo

Gen Yasuda

Kazuyoshi Hatano

Keiichiro Nakamura

Shigetaka Nakamura

Toshinori Kimura

Sadahisa Tomita

Mitsuhiro Yoshimoto

Nobuya Okabe

Ryohei Suzuki

Hitoshi Kagiwada

Kazumasa Yuasa

Koji Tahara

Toshio Hasegawa

Tomohiko Yasuoka

Masao Kashiwagi

Hidefumi Takegahara

Shinichi Mihara

Masao Nishimura

Akiomi Kono

Yoshiaki Sekiguchi

Tarou Takahashi

Yasuharu Gotou

Ikuo Inagaki

Norio Onuma

Tomohiko Yasudi

Kiyoshi Oyama

Shigetoshi Konno

Yoshiyuki Umeno

Itsuo Kondo

Yuji Nagashima

Yusuke Hitachi ConstMachCo Ltd Kajita

Tsuyoshi Hitachi Kenki Tsukubaryo Nakamura

Masao Hitachi Kenki Tsukubaryo Nishimura

Masakazu Hasa

An object of the present invention is to provide a work machine that can increase the operation speed of an actuator by a regenerating function while ensuring accuracy of position control of the actuator. For this purpose, a controller computes a target actuator supply flow rate by subtracting a regeneration flow rate from a target actuator flow rate, computes a target flow control valve opening amount on the basis of the target actuator supply flow rate, computes a target pump flow rate equal to or more than the sum of a plurality of the target actuator supply flow rates, controls flow control valves according to the target flow control valve opening amount, and controls a hydraulic pump according to the target pump flow rate.

Work machine

There is provided a work machine which can improve accuracy of control of an actuator when a pressure difference between a hydraulic pump and the actuator is large and the demanded flow rate of the actuator is small. An auxiliary flow rate controller is configured such that an opening area of a main valve changes between a maximum opening area and zero according to the opening area of a pilot variable restrictor when the opening area of the pilot variable restrictor is equal to or more than a predetermined opening area and that the opening area of the main valve is zero irrespective of the opening area of the pilot variable restrictor when the opening area of the pilot variable restrictor is less than the predetermined opening area.

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.

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.

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.

To provide a work machine that makes it possible to drive actuators faster and more accurately by supplying flows to the actuators accurately at target rates without depending on load variations in a case where the machine body is controlled automatically by command inputs of a controller, while high operability is ensured for manual operation by an operator. In a case where a machine control function is cancelled via a machine control switch, a controller cancels limitation of the flow rate of a hydraulic fluid supplied to a plurality of directional control valves, the limitation being performed by the auxiliary flow rate control devices, and in a case where the machine control function is selected via the machine control switch, the controller causes the auxiliary flow rate control devices to limit the flow rate of the hydraulic fluid supplied to the plurality of directional control valves.

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 either fluctuate in response to load fluctuations of a plurality of hydraulic actuators when an area limiting control function invalidation instruction is issued, or do not fluctuate in response to the load fluctuations of the plurality of hydraulic actuators when an area limiting control function validation instruction is issued.

Work machine with automatic and manual operating control

A hydraulically driven industrial machine having a variable displacement type hydraulic pump adapted to take in and pressurized working oil from an working oil tank, a hydraulic actuator to be driven by pressurized working oil delivered from the hydraulic pump through a control valve to perform a predetermined job, a variable return oil cooling means capable of cooling return oil from the hydraulic actuator at a varying cooling rate, an operational load detection means adapted to detect an operational load factor of the hydraulic actuator, and a control means adapted to vary the return oil cooling rate on the basis of an operational load factor detected by the operational load detection means.

Hydraulically driven industrial machine

A display device for a construction machine has a display switching means, output control means, operation detecting means, and display prohibiting means. The display switching means switches information displayed on a monitor placed in an operation cabin, where the switching is made to prevent display of unnecessary information on the monitor while the construction machine is performing work. The output control means selects display information recorded in information recording means and outputs the selected information to the monitor. The operation detecting means detects whether or not the construction machine is in a working state. When the operation detecting means detects that the construction machine is in the working state, display switching operation of the monitor is performed by the display switching means, and the display prohibiting means prohibits the display of specific information.

Monitor display for construction machine

A hydraulic excavator periodically measures its current location at predetermined time intervals by the GPS device in an inoperative state where its engine key is in the off position and sends the current location data and time data to a management server by a main controller and communicator. The management server receives the periodically sent location data at its communicator and successively stores it in its memory. The current location data and the measurement time data to provide a location confirmation service by a location information provider. Changes in location can be confirmed on a map, the movement of the hydraulic excavator can be tracked, and assistance can be given for confirmation of location and prevention of theft.

Location confirmation method and location display system of construction machine and such construction machine

The invention provides a control system for a working vehicle, which can realize higher work performance and better fuel economy in a compatible way. A controllerincludes tableand tablesfor deciding maximum pump absorption torques and engine output torques based on an engine revolution speed, and selectorsfor switching over the decided maximum pump absorption torques and engine output torques depending on a work performance mode or a fuel economy mode is selected. A pump absorption torque characteristic for the fuel economy mode is set so as to provide a relative small maximum pump absorption torques TB in a high revolution range, and an engine output characteristic for the fuel economy mode is set so as to provide a relatively small engine output torque in the high revolution range.

Control device for working vehicle

A traveling hydraulic working machine has a target revolution speed of an engine commanded by an input and sensors for detecting an operating situation of a hydraulic actuator and an operating situation of a traveling system. A prime-mover revolution speed control modifies the target revolution speed of the prime mover when the operating situation of the hydraulic actuator and the operating situation of the traveling system come into respective particular states, and controls the revolution speed of the prime mover, With the traveling hydraulic working machine, in the combined operation of traveling and working a hydraulic actuator, work can be performed on the basis of the engine revolution speed intended by an operator. When a working load varies, the engine revolution speed is automatically controlled.

Traveling hydraulic working machine

Assessment information needed to calculate a used vehicle assessment value of a hydraulic excavatoris input to a portable telephoneand is then transmitted from the portable telephone. The transmitted assessment information is received at a manufacturer's base stationat a remote location. The used vehicle assessment value of the hydraulic excavatoris calculated based upon the received assessment information, and history information and operation information on the hydraulic excavatorread out from an operation information databaseand a history databasein correspondence to an ID number assigned to the hydraulic excavator which is included in the assessment information.

Construction machine management apparatus and construction machines management system

An antitheft system can be provided by constructing such that, when a stop signal has been inputted from an engine, a main controlleroutputs, until a first predetermined time Ts elapses, a turn-on signal to switchesto perform a similar antitheft processing as in an operation of the engineand after an elapse of the first predetermined time Ts, instructs the switchto repeat a turn-on and turn-off at predetermined time intervals &#x394;t, and, whenever the switchis brought into a turned-on position, detects a position at that time by a position detecting controllerand compares the position with a position at the time of an engine stop to determine whether or not a theft has taken place. Owing to this construction, it is no longer necessary to always feed power to the position detecting controllerduring the stop of the engine, thereby making it possible to cut down the feeding of as much power to the controlleras a time elapsed during which the switchis kept off. The antitheft system can, therefore, minimize the power consumption of a control system during the engine stop.

Antitheft device

To permit using hold-side pressure oil in a first hydraulic cylinder for the acceleration of a second hydraulic cylinder upon performing a combined operation of the first and second hydraulic cylinders, a hydraulic drive system is provided with a main hydraulic pump, a boom cylinderand an arm cylinder, a directional control valvefor a boom and a directional control valvefor an arm, and a boom control deviceand an arm control device. The hydraulic drive system is also provided with a pressure oil feed means for feeding pressure oil in a rod chamberof the boom cylinderto an upstream side of the directional control valvefor the arm when a bottom pressure of the arm cylinderhas increased to a high pressure equal to or higher than a predetermined pressure. This pressure oil feed means includes a flow combiner valvearranged in a reservoir linewhich can communicate to the rod chamberof the boom cylinder. When the bottom pressure of the arm cylinderis the predetermined pressure or higher, the flow combiner valvemaintains a communication line, which communicates the reservoir lineand the upstream side of the directional control valvefor the arm with each other, in a state that pressure oil can be fed to the upstream side of the directional control valvefor the arm.

Hydraulic drive device

Growing community of inventors

Ryugasaki, Japan

Genroku Sugiyama