Patent attributes
Disclosed is a hydraulic circuit for construction equipment, having a floating function for ground leveling work, which can be implemented by a main control valve. According to the present invention, provided is a flow control valve for construction equipment, having a floating function, comprising: a valve body having, formed therein, a supply path in communication with a pump path to which hydraulic oil is supplied from a hydraulic pump, and first and second actuator paths connected to a hydraulic cylinder driven by the hydraulic oil from the hydraulic pump; a spool switchably built into the valve body for, when switched, communicating the supply path into the first and second actuator paths so as to supply, to the hydraulic cylinder, the hydraulic oil from the hydraulic pump via the supply path and the first actuator path and return, to a tank path, the hydraulic oil discharged from the hydraulic cylinder via the second actuator path; a recycling path for supplying, to a small chamber of the hydraulic cylinder, a portion of the hydraulic oil returned from a large chamber of the hydraulic cylinder to the tank path and recycling the same; and a valve for floating conversion, installed at a predetermined position of the recycling path, wherein, in case of conversion to a floating state by application of pilot pressure to the valve for floating conversion, the large chamber and the small chamber of the hydraulic cylinder are communicated, and a path for supplying the hydraulic oil to the small chamber of the hydraulic cylinder and the recycling path are communicated so as to enable a bi-directional flow of the hydraulic oil.
