Hitachi Construction Machinery Co., Ltd.

Kazuo Chounan

Koji Hyodo

Tetsuji Tanaka

Masaki Yoshikawa

Hiroyuki Azuma

Atsushi Shimazu

Yasunori Miyamoto

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 work machine includes a thermostat provided upon a path that conducts the cooling water to the radiator, and that opens and closes the path according to a temperature of the cooling water, a fan device that blows external air at the radiator, an output changeover switch that changes over output of the engine between high and low, a rotational speed setting unit that sets a rotational speed for the fan device according to the temperature of the cooling water, and a rotational speed adjustment unit that adjusts rotational speed of the fan device, wherein, within a temperature range for the cooling water in which the thermostat is fully opened from fully closed, the rotational speed of the fan device to be lower when the output changeover switch is changed over so as to limit the output of the engine.

Work machine

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.

Growing community of inventors

Moriya, Japan

Kazuo Chounan