FORKLIFT HYDRAULIC CONTROL APPARATUS

摘要

An outlet port (Pa) of a hydraulic pump/motor (PM) and a bottom chamber (1 b) of a lift cylinder (1) are connected to each other by a hydraulic fluid passage (Ka). A hydraulic fluid passage (Kd) that is connected to a hydraulic fluid tank (Ta) is formed to branch off the hydraulic fluid passage (Ka). A flow control valve (6) is provided in the hydraulic fluid passage (Kd). The flow control valve (6) controls the hydraulic fluid delivered from the lift cylinder (1) when the fork (F) is lowered, thereby regulating the flow rate of hydraulic fluid supplied to the hydraulic pump/motor (PM) and the flow rate of hydraulic fluid supplied to the hydraulic fluid tank (Ta). If regenerative operation can be performed, the flow control valve (6) is closed and hydraulic fluid is delivered to the hydraulic pump/motor (PM). If regenerative operation cannot be performed, the flow control valve (6) is opened and hydraulic fluid is delivered to the hydraulic fluid tank (Ta). In either case, the fork (F) can be lowered at an instructed speed.