Hitachi Construction Machinery Co., Ltd.

Kcm Corporation

Masaki Yoshikawa

Koji Hyodo

Isamu Aoki

Tetsuji Tanaka

Yasuo Yamazaki

Hiroki Nakazono

Kazuo Chonan

Nobuyuki Hidaka

Kazunori Nakamura

Nobuhiro Suzuki

Hidenobu Tsukada

Ei Takahashi

Youichi Kowatari

Wataru Isaka

Atsushi Shimazu

Yasunori Miyamoto

Tadayoshi Aoki

Kazuyuki Ito

Katsutaka Hara

Kouji Shimazaki

Tomohiro Ueda

Hiroshi Sakamoto

Takaaki Ishii

Kazuhiko Hiraoka

Tomoyuki Miyata

Hiroyuki Azuma

Akitaka Takeuchi

Keigo Kikuchi

Masaki Nukii

Kazunori Komatsu

Kentaro Itoga

Hirofumi Oouchi

Takayoshi Murahashi

Shigeki Tokita

Koji Shimazaki

Keisuke Naitou

Koji Takano

Katsuyuki Kirita

Keiichirou Nakamura

Genichiro Ishimaru

Hiroaki Yada

Shunya Kokubo

Kazuo Chounan

Tsuyoshi Takeyama

Satoshi Kan

Tomoo Takahashi

Seiji Nakagawa

Jujitsu Murota

Kosei Suzuki

Takashi Ishii

Masakazu Kaitou

Takuya Shimomura

Provided is a work vehicle capable of reducing the fuel consumption while maintaining the working efficiency. A wheel loadercomprising a vehicle body controllerA for controlling an engine, wherein the vehicle body controllerA limits an upper limit rotational speed of the enginebased on an accelerator pedal step-on amount α, a brake pedal step-on amount β, a torque converter speed ratio e which is a ratio of a rotational speed of a torque converter, a discharge pressure Pof a loading hydraulic pump, and a stroke amount Sof lift arm cylindersor a stroke amount Sof a bucket cylinder

Work vehicle

Provided is a loading work vehicle capable of improving work efficiency even when working on a slippery road surface. An HST-traveling-drive wheel loadercomprises a step-on amount detection sensor, a discharge pressure detection sensor, a mode switch device, and a controller. The controlleris configured to: determine whether a limit mode is selected by the mode switch device; specify an operation state of the wheel loaderwhen determining that the limit mode is selected; limit maximum traction force to a first set value which is set based on a static friction coefficient μ and vehicle weight when specifying that a bucketis pushed into a natural ground; and increase the maximum traction force from the first set value when specifying that excavation of the natural groundis started.

Loading work vehicle

Provided is a work machine capable of notifying that maintenance is necessary due to continuation of clogging in a cooling device or decrease in cooling performance. A wheel loaderincluding a radiatorand an oil coolercomprises a controllerA configured to determine a clogging continuation state of the radiatoror the oil cooler. The controllerA determines whether clogging is occurring in the radiatoror the oil coolerbased on outside air temperature AW and cooling water temperature CW or hydraulic oil temperature HW, determines whether the clogging continues based on a clogging occurrence ratio R, Rwhile an engineis operating, and outputs a notification command signal for providing the alarm buzzerand the user management systemwith a command to notify that maintenance is necessary when it is determined that the clogging continues.

Work machine

In an unloaded state of the bucket (), a control device () calculates an unloaded moment (M) around a hinge pin G from the pressure of the lift arm cylinder that is detected by pressure sensors (), the angle of a lift arm that is detected by a lift arm angle sensor, and dimension data extracted from a vehicle body information database (). In a loaded state of the bucket, the control device calculates a loaded moment (M) around the hinge pin G from the pressure of the lift arm cylinder, the angle of the lift arm, and the dimension data extracted from the vehicle body information database. The control device calculates the load (W) on the bucket by dividing the difference between the unloaded moment and the loaded moment by the horizontal distance (L) between the hinge pin and the gravity center position of the bucket.

Wheel loader and bucket load calculation method

Construction machine display screen with graphical user interface

A work vehicle, includes: a lift arm rotatably linked to a front portion of a vehicle body of a work vehicle so as to be allowed to swing along an up/down direction; an operation lever that can be operated within a range between a raising operation end position and a lowering operation end position, and is operated to raise and lower the lift arm; an up detent mechanism having a holding function for holding the operation lever at the raising operation end position once the operation lever is operated to the raising operation end position; and a down detent mechanism having a holding function for holding the operation lever at the lowering operation end position once the operation lever is operated to the lowering operation end position, wherein: when an angle of the lift arm becomes greater than a predetermined upper limit, the holding function of the up detent mechanism and the holding function of the down detent mechanism are disengaged.

Armrest for a working vehicle

An engine control device for a work vehicle decides that an idling stop condition is established when the front device is in the unengaged state, the steering device is in the unengaged state, the accelerator pedal is in the non-operation state, either the transmission is in the neutral state or the parking brake device is in the engaged state or the transmission is in the neutral state and also the parking brake device is in the engaged state, and the service brake device is in the unengaged state, and stops an engine when it is decided that it passes the predetermined length of time since it was decided that the idling stop condition was established.

Engine control device for work vehicle

To provide a travel control device for a working vehicle, including a speed change lever that is applicable even when a transmission in which speed stages are set to be larger by one stage is applied, the travel control device comprises a switching device () that switches speed changed by a transmission () either manually or automatically, a speed stage selecting device () that selects a speed stage out of a plurality of speed stages of the transmission (), and a first speed selecting device () that changes the speed stage manually down to a first speed separately from the speed stage selecting device (), regardless of a switching state of the switching device (), wherein the speed stage selecting device () selects the speed stages including a second speed or more but excluding the first speed, and a control device () is further provided, which controls the transmission () based on instructions sent from the switching device (), the speed stage selecting device (), and the first speed selecting device ().

Operation vehicle travel control device

An engine speed control device for an industrial vehicle includes an approach detector that detects an approach of the industrial vehicle to an object to be approached; and an engine speed controller that restricts an upper limit of a rotation speed of an engine when the approach detector detects an approach of the industrial vehicle to an object to be approached.

Engine speed control device for industrial vehicle

A work vehicle control device includes: a rotation speed control unit that controls an engine rotation speed in correspondence to an accelerator pedal operation quantity indicating an operating extent of an accelerator pedal; a speed ratio detection unit that detects a ratio of speed at an input shaft and at an output shaft of a torque converter, which is disposed between the engine and wheels; a decision-making unit that makes a decision that a fuel efficiency deteriorating condition exists if the torque converter speed ratio is less than a predetermined value or if the torque converter speed ratio is equal to or greater than the predetermined value and a target engine rotation speed corresponding to an operation of the accelerator pedal is greater than a preset value; and an informing unit that informs results of the decision made by the decision-making unit.

Work vehicle control device

There are provided: a first circuit for traveling HC, formed through a closed circuit connection of a variable displacement hydraulic pumpand a variable displacement hydraulic motor, that includes a motor control unitthat controls a displacement of the hydraulic motor; a second circuit for working HCthat drives a work hydraulic actuatorby pressure oil from a work hydraulic pump; and a maximum value control unit that controls a maximum displacement of the hydraulic motorin accordance with load pressure Pf in the second circuit HC. The maximum value control unit decreases the maximum displacement to a minimum limit qcorresponding to a maximum load pressure Pr in the second circuit when load pressure Pf in the second circuit exceeds a predetermined value Ps.

Travel control apparatus for working vehicle

A motor control device for a working vehicle includes: a travel drive device that transmits rotation of a motor to wheels through a torque converter; a first selection device to be operated so as to select one of a power mode and an economy mode; a second selection device that is different from the first selection device; a mode switching device that switches from the economy mode to the power mode if the second selection device is operated in a state where the economy mode has been selected by the first selection device; and a speed restriction device that, when the economy mode is set, restricts a maximum rotational speed of the motor to a lower speed side than that when the power mode is set.

Motor control device for working vehicle

A working vehicle motor control device includes: a rotational speed control device that controls a motor rotational speed in accordance with an operation amount of an accelerator pedal; a travel drive device that transmits rotation of the motor to wheels through a torque converter and a transmission; a speed ratio detection device that detects a speed ratio of an input shaft and an output shaft of the torque converter; and a speed restriction device that restricts a maximum rotational speed of the motor in accordance with a speed ratio detected by the speed ratio detection device. In the working vehicle motor control device, the speed restriction device restricts the maximum rotational speed when a detected speed ratio is in an acceleration region of the motor rotational speed to less than the maximum rotational speed when a detected speed ratio is in a non-acceleration region.

A control apparatus for a working vehicle includes a travel circuit HCformed through a closed circuit connection of a variable displacement hydraulic pump driven by an engine and a variable displacement hydraulic motor, a work circuit HCthat includes a work hydraulic pump driven by the engine and a work hydraulic actuator that operates by pressure oil from the work hydraulic pump, a relief valve that relieves high pressure oil of the travel circuit HC, a rotation speed control unit that controls the engine rotation speed in correspondence to an accelerator pedal operation amount, a state detection unit that detects a vehicle state of high load travel and high load work, and a speed limitation unit that reduces an engine rotation speed upper limit when the vehicle state of high load travel and high load work is detected.

Control apparatus for working vehicle

Growing community of inventors

Kasama, Japan

Masaki Yoshikawa