A hydraulic drive device (16) for cargo handling vehicle has: a tank (19); a pump (17) for drawing in a hydraulic oil from the tank and supplying the hydraulic oil to hydraulic cylinders; an electric motor (18) for driving the pump; a solenoid-controlled proportional valve (48) disposed between an inlet port of the pump and a bottom chamber of an up-and-down hydraulic cylinder (4) and configured to open with a valve travel depending upon a control input of a descent control of an up-and-down control member; a pressure compensation valve (50) disposed between a branch portion located between the pump and the solenoid-controlled proportional valve and the tank and configured to open with a valve travel depending upon a pressure difference between pressures upstream and downstream of the solenoid-controlled proportional valve; and a valve (53) disposed between the pressure compensation valve and the tank and configured to be switched between an open position and a close position.
Hydraulic drive device for cargo handling vehicle
Hydraulisch angetriebene Vorrichtung für Frachtumschlagfahrzeug
Dispositif d'entraînement hydraulique pour véhicule de manutention de cargaison
2016-05-04
Patent
Elektronische Ressource
Englisch
IPC: | B66F HOISTING, LIFTING, HAULING, OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD , Hub-, Verhol- oder Schubvorrichtungen, soweit nicht anderweitig vorgesehen, z.B. Vorrichtungen mit unmittelbarer Krafteinwirkung auf die Last / F04B Verdrängerkraft- und Verdrängerarbeitsmaschinen für Flüssigkeiten , POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS / F15B SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL , Druckmittelbetriebene Systeme allgemein |