HYDRAULIC SYSTEM FOR EXCAVATOR USING NEGATIVE CONTROL VALVE AND PRESSURE SENSOR

摘要

The present invention relates to a hydraulic system for excavators using a negative control valve and a pressure sensor. The hydraulic system for excavators individually senses a negative pressure signal and a positive pressure signal of a remote control valve, using a negative control valve and a pressure sensor, without using a pressure switching valve for generating positive pressure and a shuttle valve for detecting the pressure of a signal having greater pressure among pilot signals and then controls the discharge flow rate in a method of controlling the operation of a pump by a control signal generated according to the execution process of an program having a pre-input pressure signal achieved by a main control unit. Therefore, the hydraulic system for excavators can solve the following problems: a design problem of the pressure switching valve; a setting problem for being matched with a pump; a problem that a circuit structure is complicated due to the use of the pressure switching valve and the shuttle valve; a problem of increase of time and costs; and a problem of unstable operation and implementation.