Abstract: A hydraulic device for industrial vehicles. A first motor drives a first hydraulic pump and a second hydraulic pump. The first hydraulic pump supplies hydraulic fluid to a power steering device and a brake device. The second hydraulic pump supplies hydraulic fluid to a carriage device. If an increased amount of hydraulic fluid need be supplied to the carriage device, a second motor drives a third hydraulic pump. Thus, together with the second hydraulic pump, the third hydraulic pump supplies hydraulic fluid to the carriage device.

Abstract: A hydraulic system for a forklift includes a handle angle sensor for outputting a rotational angle signal indicative of a rotational angle of a handle, a wheel angle sensor for outputting a wheel angle signal indicative of a steering angle of wheels, and a controller. The controller calculates a rotation angular velocity of the handle based on the rotational angle signal from the handle angle sensor to discharge from the hydraulic pump the hydraulic fluid of a flow rate in conformity with this rotation angular velocity, and controls the flow rate of the hydraulic fluid supplied to the power steering cylinder based on the rotational angle signal from the handle angle sensor and the wheel angle signal from the wheel angle sensor to steer the wheels in conformity with the rotational angle of the handle.