HYDRAULIC CONTROL DEVICE OF FORKLIFT TRUCK

• Main Authors: UNO, TAKASHI, UEDA, YUKI, YOKOMACHI, NAOYA, MATSUO, TSUTOMU
• Format: Patent
• Language: English; French; German
• Published: 19.10.2016
• Subjects: BLASTING; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR; FLUID-PRESSURE ACTUATORS; FLUID-PRESSURE ACTUATORS, e.g. SERVO-MOTORS; HAULING; HEATING; HOISTING; HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDEDFOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCEDIRECTLY TO THE SURFACE OF A LOAD; HYDRAULICS OR PNEUMATICS IN GENERAL; LIFTING; LIGHTING; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; TRANSPORTING; WEAPONS

A hydraulic control device of a forklift truck includes a first hydraulic cylinder [14], a first instructing member [22], a second hydraulic cylinder [19], a second instructing member [23], a hydraulic pump [30], an electric motor [31], a first oil passage [K1], a lowering control valve [32], a second oil passage [K2] that is branched from the first oil passage [K1] at a junction [Q], a flow control valve [37], a first pilot passage [51] through which pressure in the first oil passage [K1] at a position between the first hydraulic cylinder [14] and the lowering control valve [32] is applied to a first accommodating chamber (43) of the flow control valve [37] as the pressure [P1] upstream of the lowering control valve [32], and a second pilot passage [52] through which pressure in the first oil passage [K1] at a position between the lowering control valve [32] and the hydraulic pump [30] is applied to a second accommodating chamber (46) of the flow control valve [37] as the pressure downstream [P2] of the lowering control valve [32].