HYDRAULIC CONTROL DEVICE FOR FORKLIFT

摘要

A hydraulic control device for a forklift includes a hydraulic pump, a single electric motor for driving the hydraulic pump, an outflow control mechanism provided between a lift cylinder and the hydraulic pump, a flow control valve provided between the outflow control mechanism and a draining portion, and a controller. When a lowering operation of a fork and either forward or rearward mast tilting operations of a mast are performed at the same time, the controller controls the electric motor based on a target speed of the hydraulic pump that is necessary for causing operation at an instructed speed that is in accordance with the operation amount of a lifting/lowering instruction member or the operation amount of a tilting instruction member. The flow control valve controls the flow rate of hydraulic fluid from the lift cylinder to the hydraulic pump and the flow rate from the lift cylinder to the draining portion in accordance with the difference between the actual rotation speed of the hydraulic pump and the target rotation speed of the hydraulic pump that is necessary for lowering the fork at the instructed speed corresponding the operation amount of the lifting/lowering instruction member.