Lift control mechanism and method

摘要

A lift attached to a truck has a tail gate supported by at least one hydraulic lift cylinder (1) and at least one tilt cylinder (2) for respectively lifting the tail gate as a whole and rotating it for opening and closing. A control system for moving such a tail gate up and down as a whole and rotating it to open and close it is provided with a power unit including a hydraulic pump (6), an electric motor (5) for the hydraulic pump, and a plurality of valves (4,8,9) for selectably allowing or not allowing transport of a hydraulic liquid by the hydraulic pump into the hydraulic cylinders, a sensor (3) for measuring the slope angle of the tail gate, external switches (10,11) and a controller (7) which serves to transmit output signals to the motor and to the valves in response to input signals from the sensor and the external switches and is capable of stopping rotary motion of the tail gate at a horizontal position irrespective of the slope of the vehicle and staring and stopping the rotary motion of the tail gate gradually.