The invention relates to the technical field of engineering machineries, and discloses a main arm variable amplitude controlling system for a crane and the crane. The security reliability of main arm variable amplitude control under various conditions of the crane is improved. The system comprises a proportional source power reversing valve group and a variable amplitude oil cylinder, wherein the proportional source power reversing valve group is provided with a first working position which enables a first working oil hole and a second working oil hole to be respectively communicated with an oil inlet and an oil returning hole and a second working position which enables the first working oil hole and the second working oil hole to be communicated with the oil returning hole and the oil inlet; an oil inlet of the proportional source power reversing valve group is connected with a pressure oil path; the oil returning hole of the proportional source power reversing valve group is connected with the oil returning path; the first working oil hole is connected with a rod cavity of a variable amplitude oil cylinder; the second working oil hole is connected with a rodless cavity of the variable amplitude oil cylinder; the main arm variable amplitude control system also comprises a switch valve and a counterbalance valve; an oil inlet of the switch valve is connected with an oil supply path during dropping of variable amplitude; an oil outlet of the switch valve is connected with an oil inlet of the counterbalance valve; an oil outlet of the counterbalance valve is connected with an oil returning path.
Main arm variable amplitude controlling system for crane and crane
2015-04-22
Patent
Electronic Resource
English
Amplitude-variable control system of main arm of crane and crane
European Patent Office | 2015
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