液压挖掘机振动掘削系统动态特性研究

Research on Dynamic Characteristics of Vibratory Excavation System in Hydraulic Excavator

以液压挖掘机振动减阻为目的,对振动掘削系统动态特性进行研究。为了从理论上分析系统特性,建立振动掘削系统数学模型,确立比例放大环节、电-机械转换环节、先导阀-主阀环节的传递函数。并建立振动掘削系统动态特性仿真模型,通过定压差压力突变法对阀芯位移、流量阶跃响应特性进行仿真分析,对振动掘削系统频率响应特性进行仿真分析。仿真结果表明:阀芯位移、流量阶跃响应调整时间分别为0.06 s、0.18 s,超调量分别为4.01%、3.17%;矩形波、正弦波、三角波三种波形下系统流量控制误差分别为8.27%、5.5%、7.2%。最后,以某90型液压挖掘机为平台对模型进行试验验证。

To reduce the resistance for vibratory excavation of hydraulic excavator, the dynamic characteristics of vibratory excavation system is researched. In order to analyze the dynamic characteristics theoretically, the mathematical model of vibratory excavation system is set up, each transfer function of proportional amplification, electrio-mechanic transformation, and the pilot valve-main valve link is built. The simulation model of dynamic characteristics of vibratory excavation system is established. The simulation analysis of step response characteristics of both the spool displacement and flow are conducted by mutations of pressure with constant pressure difference. The simulation analysis of frequency response characteristics of vibratory excavation system is also conducted. The simulation results show that the adjusting time of the spool displacement and flow response are 0. 06s and 0. 18s respectively, and their overshoots are 4.01% and 3.17%. The flow control error of the rectangle signal, sinusoidal signal and triangle signal are 8.27% ,5.5% and 7.2% respectively. Finally, a verification test of the simulation model is conducted through a real 9t hydraulic excavator.