FORKLIFT HYDRAULIC CONTROL APPARATUS

• Main Authors: MATSUO TSUTOMU, GOTO TETSUYA, UEDA SUKENORI, ISHIKAWA HIROHIKO, MORITA JUNICHI
• Format: Patent
• Language: English
• Published: 19.08.2013
• 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

PROBLEM TO BE SOLVED: To obtain effects by use of regeneration operation while simplifying configurations.SOLUTION: A discharge port Pa of a hydraulic pump motor PM and a bottom chamber 1b of a lift cylinder 1 are connected by an oil passage Ka, to use the oil passage Ka as a supply/discharge channel. In the oil passage Ka, an oil passage Kd to be connected to a hydraulic fluid tank Ta (drain side) is formed in a branched state. A flow rate control valve 6 is disposed in the oil passage Kd. The flow rate control valve 6 controls the flow rate of hydraulic fluid to be supplied to a hydraulic pump motor PM and the flow rate of hydraulic fluid to be supplied to a hydraulic fluid tank Ta, the hydraulic fluid being discharged from the lift cylinder 1 when the fork F is lowered. Consequently, if regeneration operation is enabled, the flow rate control valve 6 is closed and hydraulic fluid is circulated to the hydraulic pump motor PM. On the other hand, if regeneration operation is disabled, the flow rate control valve 6 is opened and hydraulic fluid is circulated to the hydraulic fluid tank Ta and thereby, in either case, the fork F can be lowered at a designated speed.