A Hydraulic Control Device for Boom Cylinder of Construction Equipment

摘要

The present invention relates to a boom cylinder hydraulic control system of a construction machine. The boom cylinder hydraulic control system of a construction machine includes: a boom cylinder to operate a boom up and down; a control valve which controls the supply or the discharge of pressurized oil of a hydraulic pump to the boom cylinder; a descending-side discharging passage which discharges the pressurized oil of a head-side fluid chamber to an oil tank; a descending-side controller controlling opening and closing of the descending-side discharging passage; an ascending-side discharging passage discharging the pressurized oil of a rod-side fluid chamber to the oil tank; an ascending-side controller controlling opening and closing of the ascending-side discharging passage; and a selection switch controlling the opening and closing of the ascending-side controller or the descending-side controller. According to the present invention, the boom cylinder hydraulic control system of a construction machine can easily control the boom and reduces oil usage and prevents the boom from descending by the self-weight during a work using a breaker and a bucket.