Flow control system for small excavators using negative pressure

摘要

The present invention comprises a main pump equipped with a horsepower control piston unit that adjusts the discharged flow rate according to the inclination angle of the swash plate and changes the inclination angle of the swash plate, and a main control valve that controls the flow of hydraulic oil supplied from the main pump to the working device. A flow control system for a small excavator configured, comprising: a pressure setting unit connected to the swash plate to maintain an inclination angle by an elastic force; A chamber unit installed inside the housing of the main pump to receive a negative pressure formed by a change in a bypass flow rate passing through the main control valve; Negative flow control piston part that one side is connected to the pressure setting part side and the other side is located inside the chamber part so that the magnitude of the force against the pressure setting part is varied by the pressure change of the chamber part to adjust the angle of the swash plate It provides a flow control system for a small excavator using a negative pressure characterized in that it includes.