HYDRAULIC SYSTEM OF CONSTRUCTION EQUIPMNET, HAVING FLOAT FUNCTION

摘要

The present invention relates to a hydraulic system of construction equipment, having a float function, comprising: a hydraulic pump and a pilot pump for supplying hydraulic oil for the operation of construction equipment; a remote control valve for outputting a pilot signal corresponding to the operation amount of an operation lever; a hydraulic cylinder for the construction equipment, which is connected to the hydraulic pump; a main control valve provided to the discharge path of the hydraulic pump and controlling the starting, stopping and direction conversion of the hydraulic cylinder at the time of spool conversion; a solenoid valve to be converted to an opening position at the time of on-operation of a float function switch; and a two-stage port relief valve provided to a path between the main control valve and the hydraulic cylinder for the construction equipment and converted at the time of operation of the float function switch so as to return the hydraulic oil of the large chamber of the hydraulic cylinder to the hydraulic tank, thereby lowering the construction equipment.