The invention provides a hydraulic circuit comprising: a plurality of hydraulic pumps that are hydraulic pressure supply sources; a flow-dividing valve that prioritizes the supply of hydraulic fluid from these hydraulic pumps to steering and supplies excess hydraulic fluid to an actuator for cargo handling; and a flow rate adjustment valve provided between the flow-dividing valve and the actuator for cargo handling. The hydraulic circuit has, as the plurality of hydraulic pumps, one main pump and at least one sub-pump, and is characterized by comprising a switching valve which is provided between the sub-pump and the flow-dividing valve, and which switches between: a first state in which the hydraulic fluid from the sub-pump is guided to the upstream side of the flow-dividing valve if the discharge flow rate from the main pump is less than a prescribed discharge flow rate or if the main pump rotation speed is lower than a prescribed rotation speed; and a second state in which the hydraulic fluid from the sub-pump is guided to a bypass path that merges on the downstream side of the flow-dividing valve and on the upstream side of the flow rate adjustment valve, if the discharge flow rate from the main pump is greater than the prescribed discharge flow rate or the rotation speed of the main pump is greater than the prescribed rotation speed.
Hydraulic circuit and cargo-handling vehicle
2015-08-26
Patent
Electronic Resource
English
IPC: | F15B SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL , Druckmittelbetriebene Systeme allgemein / B62D MOTOR VEHICLES , Motorfahrzeuge / 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 |