CONSTRUCTION MACHINERY

PROBLEM TO BE SOLVED: To provide construction machinery capable of operating a working machine even during the use of an attachment. SOLUTION: Since a hydraulic circuit is constituted of at least one set of hydraulic pumps 24 and 25, a plurality of direction selector valves 28 or 37 supplying pressure oil discharged from the hydraulic pumps 24 and 25 to an actuator of the working machine 11 and the attachment, a flow adjusting means 43 for adjusting the flow of the pressure oil branched from the hydraulic pumps 24 and 25 and a direction selector valve 44 supplying the pressure oil adjusting the flow by the flow adjusting means 43 to the attachment in responding with action of the direction selector valves 28 or 37 switching the pressure oil to the actuator, the pressure oil discharged from the hydraulic pumps 24 and 25 is supplied to the attachment even during the work by the working machine 11 so that the working machine 11 and the attachment can be simultaneously operated, and accordingly, working efficiency of the attachment can be greatly improved. COPYRIGHT: (C)2005,JPO&NCIPI