System for automatically controlling quantity of hydraulic fluid of an excavator

摘要

A control system for controlling quantity of hydraulic fluid of an excavator. The control system of this invention provides a method for controlling the quantity of the hydraulic fluid supplied to the swing motor in which in case of swinging operation for driving the swing motor in order to turn the upper frame with respect to the lower frame, the first hydraulic pump is automatically controlled by the controller in order to optimally output hydraulic fluid to timely correspond to starting of the practical swinging operation of the swing motor. The control system of this invention provides another control method for controlling the main pumps in order to output minimum quantity of fluid flow in case of sensing an abnormal operational speed, a speed not exceeding 1/2, speed of the minimum operational speed of the actuator occurring when the actuator is supplied with the minimum quantity of the hydraulic fluid from the main hydraulic pumps, occurring on the actuators due to an overload, but output a normal quantity of fluid flow in order to allow the actuators to be normally operated in case sensing a returnable speed, a speed exceeding 3/4 speed of the minimum operational speed.