Hitachi Construction Machinery Co., Ltd.

Yuuki Gotou

Hidetoshi Satake

Katsuaki Kodaka

Kazuhiro Ichimura

Hidenobu Tsukada

Kazuhiro Shibamori

Youichi Kowatari

Keiichiro Nakamura

Yuuji Nagashima

Kouta Fujieda

Kouji Ishikawa

Kazunori Nakamura

Yoichi Kowatari

Yutaka Watanabe

Hideo Karasawa

Nobuei Ariga

Yasushi Arai

Yousuke Yamanobe

Motoyuki Yabuuchi

Atsushi Kanda

Wataru Kondou

A work machine includes: a work device; an operation device operating the work device; a first controller controlling operation of the work device on the basis of operation of the operation device; and a second controller determining that an auto idle condition is satisfied and performing auto idle control that decreases an engine revolution speed to an idle revolution speed in case the operation device is not operated for a predetermined time. The first controller diagnoses presence or absence of a failure in the first controller when supply of power to the first controller is started. The second controller performs power interruption control that interrupts the supply of the power to the first controller in case the auto idle condition is satisfied, and performs power supply control that starts the supply of the power to the first controller afterward.

Work machine

A remote management system for at least one working machine manages an upper limit of an engine rpm. A hydraulic excavator includes a controller and an instruction switch for selectively instructing three kinds of work modes. The controller includes a target rpm storage unit, a target rpm computer for selecting one of stored upper limits of the target rpm according to an instruction by an instruction switch and computing a target rpm in a range smaller than the selected upper limit, and a communication unit. A server selects a work mode, according to an instruction by an input device, and instructs the selected work mode to the controller. When the work mode is instructed from the server, the target rpm computer computes a target rpm based on the instructed work mode.

Remote management system for work machinery

A display system for a working machine displays warning information while also displaying a high-quality camera image. The display redisplays a reduced camera image at a reduction scale of 60% according to an abnormality information signal. An open areaoutside the area displaying the camera image. The display control device displays a warning icon (large size), corresponding to abnormality information regarding a filter of a DPF device, in the open area. The operator recognizes the warning and immediately stops the operation, moves to a place where the filter regeneration is possible while checking the safety of the surroundings by viewing the camera image, and then carries out the filter regeneration. After finishing, the operator confirms that the warning icon has disappeared, moves to the site of the operation while checking the safety of the surroundings by viewing the camera image (for normal times), and then restarts the operation.

Display system for working machine

A display system for a working machine displays basic information at all times and, in case of an abnormality, displays the details of the warning in addition to the basic information to enable an operator to reliably recognize details of the warning. For example, a first warning display function, upon receiving an abnormality information signal relating to a charge warning, displays an appropriate warning icon in a warning icon display region. A simplified basic-information display function, then displays simplified basic-information images and a second warning display function displays, in a free area of the display, a second warning message inclusive of a 'Charge warning' message as display details of the warning icon, and of character information relating to a simplified remedial action. The operator can then reliably recognize the 'Charge warning' and understand its details as well, by viewing the second warning message in addition to the warning icon.

There are provided: control valves-that control flow of pressure oil from the hydraulic sourceto the hydraulic actuators-; electric lever devices-that output electrical operation signals v-vin correspondence to lever operation; electromagnetic proportional valves-through which control pressures for controlling the control valves-are output; a pressure calculating unitthat calculates control pressures P-Pin correspondence to the operation signals V-v; a control unitthat controls the electromagnetic proportional valves-so that control pressures to be output from the electromagnetic proportional valves-become the control pressures P-Pthat have been calculated; a high-pressure selection circuit-that selects a higher pressure between control pressures that have been output from the electromagnetic proportional valves-; pressure detectorsandthat detect a control pressure selected by the high-pressure selection circuit-; an abnormality determination unitthat determines an abnormality in the electromagnetic proportional valves-based upon the control pressure detected by the pressure detectorsandand the control pressure calculated by the pressure calculating unit; and an inhibiting deviceandthat prohibits control of the control valves-when it is determined that an abnormality has occurred in the electromagnetic proportional valves-

Safety device for hydraulic working machine

A prime mover rotation speed control system for hydraulically driven vehicle includes: a hydraulic pump driven by a prime mover; a hydraulic motor for traveling driven with pressure oil supplied from the hydraulic pump; an operation member that outputs a travel command in accordance with an amount of operation by the operation member; a flow control device that controls one of a flow of the pressure oil from the hydraulic pump to the hydraulic motor and a flow rate of the pressure oil discharged from the hydraulic motor, based on the travel command that is output in accordance with the amount of operation by the operation member; a target rotation number outputting device that outputs a target rotation number of the prime mover based on a command; a rotation number control device that controls a rotation number of the prime mover to be the target rotation number; a vehicle speed detection device that detects a vehicle speed; and a vehicle speed calculation device that calculates a target vehicle speed in accordance with the amount of operation by the operation member. The rotation number control device includes a correction device that adjusts the target rotation number based on the vehicle speed detected by the vehicle speed detection device and the target vehicle speed calculated by the vehicle speed calculation device.

Prime mover rotation speed control system for hydraulically driven vehicle

There are provided: control valves-that control flow of pressure oil from the hydraulic sourceto the hydraulic actuators-; electric lever devices-that output electrical operation signals, which are drive instructions for the hydraulic actuators-, in correspondence to lever operation; and a control unit-andthat controls the control valves-in correspondence to the operation signals. When the determination unit determines that an operation signal is not within the normal range, the hydraulic actuators-are allowed to be driven with flow of pressure oil to the hydraulic actuators-limited more significantly than in a case where it is decided that an operation signal is within the normal range.

A pedal lock control device for work vehicle includes: a motor driving device that drives a travel hydraulic motor in response to an operation amount of a travel pedal; a locking device that locks the travel pedal in a state of being operated; an instruction device that instructs lock and unlock of the travel pedal by the locking device upon an operation by an operator; a first detection device that detects a first signal change according to an unlock operation which is an operation that reflects an intention of an operator to release the locking device and is other than an unlock operation by the instruction device; a second detection device that detects a second signal change according to an unlock operation which is an operation that reflects an intention of an operator to release the locking device and is other than the unlock operation by the instruction device, with the second signal change being different from the first signal change; and a lock control device that unlocks the locking device when an unlock operation is detected by at least one of the first detection device and the second detection device in a state where the travel pedal is locked by the locking device.

Pedal lock control device for work vehicle

A pedal lock control device for work vehicle includes: a motor driving device that drives a travel hydraulic motor according to an operation amount of a travel pedal; a locking device that locks the travel pedal in a state of being operated; an instruction device that instructs lock and unlock of the travel pedal by the locking device upon an operation by an operator; a lock intention detection device that detects an intention of an operator to permit lock of the travel pedal; and a lock control device that locks the travel pedal by the locking device when an intention of the operator to permit lock is detected by the lock intention detection device and lock of the travel pedal is instructed by the instruction device.

A rotational speed pickup(traveling speed detection means), a hydraulic pressure sensor(traveling operation detection means), a hydraulic pressure sensor(drive status detection means), and a voltage sensor(transmission shift position detection means) detect parameters regarding the traveling state of a hydraulic traveling vehicle. A control unit, a solenoid proportional valve, an engine control system, and a motor regulatordetermine the operating state of the hydraulic traveling vehicle based on the parameters regarding the traveling state, and control the equivalent displacement of the traveling system including a hydraulic traveling motorand the maximum flow rate supplied to the hydraulic traveling motoraccording to the result of determination. The pump flow rate and motor displacement are controlled according to the traveling state in this way, thereby ensuring favorable traveling performance without degrading the fuel efficiency.

Traveling control apparatus for hydraulic traveling vehicle

An engine lag down control system for construction machinery has a machinery body controller having first, second and third torque control units and a solenoid valve. The first torque control unit controls a torque control valve to a minimum pump torque corresponding to a target number of engine revolutions when a non-operated state of a control device has continued beyond a monitoring time. The second torque control unit controls the torque control valve such that the above-described minimum pump torque is held for a predetermined holding time subsequent to the operation of the control device from the non-operated state. The third torque control unit controls the torque control valve such that from a time point of a lapse of the predetermined holding time, the pump torque is gradually increased on a basis of a predetermined torque increment rate.

Growing community of inventors

Tsuchiura, Japan

Yuuki Gotou