Hitachi Construction Machinery Co., Ltd.

Kcm Corporation

Atsushi Shimazu

Koji Hyodo

Hiroyuki Azuma

Tetsuji Tanaka

Isamu Aoki

Masaki Yoshikawa

Keigo Kikuchi

Hirofumi Oouchi

Hiroki Nakazono

Shoroku Kawahara

Kazunori Nakamura

Tsuyoshi Nakamura

Nobuhiro Suzuki

Kentaro Itoga

Yasunori Miyamoto

Mitsuo Kihara

Tadayoshi Aoki

Masashi Yamashita

Kazuo Chonan

Kazuo Chounan

Tomoo Takahashi

Kohtaroh Uno

Kosei Suzuki

To improve working efficiency in an eco mode when a power mode and the eco mode have been set in a wheel loader, the wheel loader is provided with a controller having an eco mode characteristic line, a power mode characteristic line, and a lifting operation characteristic line having a matching point C located between a matching point A between a working device operating engine torque characteristic line and the eco mode characteristic line and a matching point B between the working device operating engine torque characteristic line and the power mode characteristic line. The controller includes a control portion, which controls a HST pump in accordance with the lifting operation characteristic line when lifting operation of a lift arm is detected while the eco mode has been selected by a work mode selecting portion.

Wheel loader

A work vehicle includes: a hydraulic pump driven by an engine; a rotational speed detection unit that detects an actual rotational speed of the engine; an exhaust gas purification device that purifies nitrogen oxide in exhaust gas discharged from the engine using a reducing agent solution stored in a reducing agent tank; a torque control unit that decreases output torque of the engine according to decrease of a detected remaining amount of the reducing agent solution; and a storage device that stores a threshold value not less than an engine rotational speed at which the hydraulic pump starts discharge, wherein when the actual rotational speed of the engine is not more than the threshold value, the torque control unit does not decrease the output torque of the engine regardless of the remaining amount of the reducing agent solution detected by the remaining amount detection device.

Work vehicle

A cooling fan control unit, in response to an operation performed at the rotation direction selector switch to select a reverse rotation setting while the cooling fan is rotating forward, lowers a relief pressure setting at the variable relief valve to a predetermined lower limit value over a predetermined length of time, and once the discharge pressure at the hydraulic pump detected by the pressure sensor is lowered to a predetermined switch-over pressure, executes control so as to switch the direction of flow of pressure oil to the hydraulic motor to the reverse direction by switching the direction switching valve and raises the relief pressure setting at the variable relief valve to a reverse rotation pressure setting, at which the hydraulic motor rotates in the reverse direction, over a predetermined length of time.

Cooling fan control device

A hydraulic control device for a work vehicle includes: a hydraulic pump that supplies pressure oil; an arm drive actuator that drives, with pressure oil supplied from the hydraulic pump, an arm attached to the work vehicle so as to swing the arm; a bucket drive actuator that drives, with pressure oil supplied from the hydraulic pump, a bucket attached to a front end of the arm, so as to swing the bucket; an arm drive pressure oil control valve that controls drive of the arm drive actuator by controlling pressure oil supplied from the hydraulic pump to the arm drive actuator; a bucket drive pressure oil control valve that controls drive of the bucket drive actuator by controlling pressure oil supplied from the hydraulic pump to the bucket drive actuator; an arm operation unit that controls the arm drive pressure oil control valve; a bucket operation unit that controls the bucket drive pressure oil control valve; an operating state detection unit that detects operating states of the arm drive actuator and the bucket drive actuator; and a flow control valve that restricts pressure oil to be supplied to the arm drive actuator as combined operation of the arm drive actuator and the bucket drive actuator is detected via the operating state detection unit.

Hydraulic control device for work vehicle

A working vehicle control apparatus includes: a selection device that selects a power mode or an economy mode; a determination device that determines whether or not a speed restriction condition and a load pressure have been established; an engine rotational speed restriction device that restricts a maximum rotational speed of the motor upon selection of the economy mode to a lower speed side than a maximum rotational speed of the motor upon selection of the power mode when it is determined that the speed restriction condition has been established; and a vehicle speed restriction device that restricts a maximum vehicle speed upon selection of the economy mode to a lower speed side than a maximum vehicle speed upon selection of the power mode when it is determined that a speed restriction condition has not been established.

Working vehicle control apparatus

A shift control system for an industrial vehicle includes: a vehicle speed detection device that detects a vehicle speed; a transmission device that shifts up and shifts down a speed stage of a transmission; a shift control device that permits shift up when a vehicle speed becomes equal to or greater than a shift up permission vehicle speed; a height position detection device that detects a height position of a working machine device; a forward/backward switch device that switches the industrial vehicle between forward travel and backward travel; and a shift up control switch selection device that switches between normal control, in which shift up is performed by the transmission device when the vehicle speed becomes equal to or greater than the shift up permission vehicle speed, and delay control, in which shift up timing is delayed with respect to the normal control.

Shift control system for industrial vehicle

There are provided: a pedal operation amount detection unitthat detects an operation amount s of the accelerator pedal; a speed ratio detection unitthat detects a speed ratio e of an input shaft and an output shaft of the torque converter; a load pressure detection unitthat detects a load pressure P of the hydraulic pump; a speed stage detection unitthat detects a low speed stage of a transmissioncapable of varying a speed stage between a low speed stage and a high speed stage; and a speed limiting unitthat limits a maximum speed of the engineto a lower speed upon satisfaction of following speed limitation conditions: at least a pedal operation amount s is equal to or greater than a predetermined value s, a speed ratio e is equal to or less than a predetermined value ea, a load pressure P is equal to or greater than a predetermined value Pa, and the low speed stage of the transmission has been detected.

Engine control device for working vehicle

A first hydraulic circuit leads, as clutch control pressure, pressurized oil supplied from a first hydraulic pump, to a transmission control device after regulating the pressurized oil, and leads, as torque converter operation oil, pressured oil to a torque converter, and leads pressurized oil to an oil cooler. Through a second hydraulic circuit, pressurized oil from a second hydraulic pump is distributed to a circuit portion downstream of the pressure regulation valve and upstream of a safety valve and to a circuit portion downstream of the torque converter and upstream of the oil cooler. A flow control device changes a proportion of a rate of flow in the second hydraulic circuit so that a proportion of the rate of flow to the circuit portion downstream of the torque converter and upstream of the oil cooler increases as pressure at an entrance of the torque converter increases.

Hydraulic pressure supply device for industrial vehicle

A hydraulic steering unitgenerates a control pressure corresponding to the rotational quantity and rotational direction of the steering wheelon the basis of pressurized oil of a pilot pump. Signals of pressure sensorsandused to detect the control pressure, and a signal of a front operation detection unit, are inputted into a controller. A controllerand solenoid valvesandcontrol a stroke of a steering valveso that the stroke becomes larger with increase in control pressure detected by each of the pressure sensorsand. In addition, when the operation of a front work device is detected, the controllerand the solenoid valvesandcontrol the stroke of the steering valveso that the stroke becomes larger than that provided when the operation of the front work device is not detected.

Growing community of inventors

Toride, Japan

Atsushi Shimazu