LIFTING SYSTEM AND LIFTING METHOD FOR JIB OF PROJECT MACHINE AND PROJECT MACHINE THEREOF.

摘要

Disclosed in the present invention is a lifting system for a jib of project machine. which comprises an energy storage device with an energy storage cylinder(4) and an accumulator (7),wherein the energy storage cylinder (4) comprises an upper chamber (4a), an lower chamber (4b) and an energy storage piston rod (2) connected with the jib(1), the upper part of the accumulator (7) is filled with gas and the lower part of which is filled with hydraulic oil and the accumulator (7) communicated with the lower chamber (4b) of the energy storage cylinder; a control cylinder(12), which controls the lifting of the jib (1) and comprises an upper chamber (12a), an lower chamber (12b) and a control piston rod (23) connected with the jib (1); a hydraulic pump (9), When the hydraulic pump supplies oil to the upper chamber (12a) of the control cylinder, the jib (1) is descending and the weight of the jib pushes the energy storage piston rod (2) to push the hydraulic oil in the lower chamber (4b) of the energy storage cylinder into the lower part of the accumulator to press the air in the upper part for recovering the potential energy; when the hydraulic pump supplies oil to the lower chamber (12b) of the control cylinder, the jib (1) is ascending and lifts the energy storage piston rod (2) and the pressed air in the upper part of the accumulator pushes the oil (19) in the lower part into the lower chamber (4b) to release the recovered potential energy to push the energy storage piston rod (2) for elevating the jib. The system effectively recoveries and recycles the potential energy of the descending jib, so that the energy is saved and the efficiency of the jib is improved. Also disclosed in the present invention are a project machine with the said lifting system and a lifting method of the jib using the said lifting system.