挖掘机正流量泵控液压系统的特性分析

Analysis on positive flow pump control system of hydraulic excavator

采用泵控挖掘机液压系统特性分析方法,在分析泵的输出特性的基础上,给出确定先导压力信号和控制泵排量的方法,并对泵的输出特性进行了仿真和实验研究。结果表明:正流量控制下,泵的排量由执行器流量需求和油泵的p-Q曲线动态实时调节,系统具有良好的负载流量适应性和负载敏感性,其液压系统中不存在负压,只有约0.5 MPa的背压,回油功率损失几乎为0。

Some problems were studied for the positive flow control of pump system of hydraulic excavator.Based on the analysis of pump output characteristics,the control method for pilot pressure and the pump displacement was given.The pump output characteristics were investigated by simulation and experiment.Results showed that flow was adjusted by flow required by actuator and the p-Q curve of main pump.For the positive system,the excavator had good load flow adaptability and load sensitivity.The power loss of returning oil path was almost zero.In the returning path,the negative pressure was only 0.5 MPa for the positive system.