HYDRAULIC CIRCUIT FOR CONSTRUCTION EQUIPMENT

摘要

Disclosed is a hydraulic circuit for construction equipment, the hydraulic circuit controlling a confluence flow rate supplied from a hydraulic pump to a plurality of working apparatuses when a composite work is carried out by simultaneously operating the working apparatuses. The hydraulic circuit, according to the present invention, comprises: a CBP valve provided at the furthest downstream side of a supply flow path for a first hydraulic pump; a boom cylinder and a bucket cylinder that are driven by a hydraulic oil of a second hydraulic pump; a bucket control valve that controls the flow direction of the hydraulic oil supplied from the second hydraulic pump to the bucket cylinder when being switched; a first boom control valve that controls the flow direction of the hydraulic oil supplied from the second hydraulic pump to the boom cylinder when being switched; a second boom control valve that supplies hydraulic oil of the first hydraulic pump to the bucket cylinder or the boom cylinder through a joint flow path when being switched; and a bucket joint shut-off valve provided on the joint flow path, wherein the bucket joint shut-off valve is switched by driving the boom cylinder or the bucket cylinder when a composite work is carried out, and shuts off the confluence flow rate supplied from the first hydraulic pump to the bucket cylinder due to the closure of the joint flow path when being switched and supplies the confluence flow rate to the boom cylinder through the second boom control valve.