Nissan Motor Company Limited

Mitsubishi Heavy Industries Limited

Mitsubishi Nichiyu Forklift Co., Ltd.

Takuya Nakada

Kensuke Futahashi

Toru Saito

Keiji Ito

Megumu Tsuruta

Yusuke Kinouchi

Katsumi Ueda

Ryuichi Umehara

Masaru Higuchi

A forklift () according to the present invention includes: an engine (); a hydraulically-operated device for cargo handling (); a pump for cargo handling () that is driven by the engine (); hydraulic piping for cargo handling () that connects the pump for cargo handling () and the hydraulically-operated device for cargo handling (); discharge piping () that branches from the hydraulic piping for cargo handling () and is connected to a tank (); a switching valve () capable of switching the opening and closing of the discharge piping (); a control device () that closes the discharge piping () when the rotation speed of the engine () is larger than a predetermined value, and opens the discharge piping () when the rotation speed of the engine () is less than or equal to a predetermined value; and a sub-relief valve () that adjusts the flow rate of hydraulic oil that is discharged from the discharge piping () to the tank (), on the bases of the pressure or the flow rate of the hydraulic oil.

Industrial vehicle

A control system of an industrial truck includes a first switch, a second switch and a hydraulic circuit. The first switch detects whether an operator sits on a seat, and carries out a first operation based on the result. The second switch detects whether a device for operating an actuator is operated, and carries out a second operation based on the result. The hydraulic circuit is used for operating the actuator. It a control valve, a first circulating line, a hydraulic line and a drive lock valve. The control valve includes a spool whose position is changed by the device. The first circulating line includes the control valve, through which the hydraulic fluid circulates. The hydraulic line connects the spool with the actuator. The drive lock valve is provided for the hydraulic line and blocks the hydraulic line, based on the first operation and/or the second operation.

Control system of industrial truck and controlling method of the same

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Tokyo, Japan

Takuya Nakada