泵阀复合进出口独立控制液压挖掘机特性研究

传统四边联动阀控制液压执行器可控性差、在超越负载工况能耗大。为改进这些不足,提出动臂、斗杆液压缸和回转液压马达采用泵阀复合、流量压力匹配进出口独立控制、铲斗液压缸与行走液压马达采用原有四边联动阀的液压挖掘机整机方案。建立液压挖掘机机械结构多刚体动力学与电液系统联合的数字样机,利用该样机分别对采用负载敏感系统和新回路系统控制的动臂、斗杆和回转马达三个执行机构动静态性能和能耗特性进行研究。进一步构建基于上述原理的试验测试样机,试验结果表明所建立数字样机具有较高的准确性;采用流量匹配进出口独立控制方法可以显著降低阀口工作压差,提高能量利用效率,减小执行机构压力冲击,提高整机运行平稳性。

Research on the Performance of Hydraulic Excavator with Pump and Valve Combined Separate Meter In and Meter Out Circuits

Conventional hydraulic actuator is controlled by mechanically connected orifices valve. This controllability of this method is poor and the energy consumption is huge especially under the over-running condition. So a novel system configuration is presented, in which boom cylinder, stick cylinder and swing motor are controlled with separate meter in and meter out technology, bucket cylinder and travel motors are controlled with conventional valves. A virtual prototype is established,which consists of the hydraulic excavator mechanical structure with multi-body dynamics and electro-hydraulic system. The dynamic, static performances as well as the energy consumption characteristics of the boom, arm and swing actuators are investigated under the condition of load sensing hydraulic system and the proposed system. After that, the physical prototype based on the proposed configuration system is established and its performance is tested. The experimental results show that the accuracy of the virtual prototype is validated, the proposed configuration system can significantly decreases the pressure losses through the valve and improve the energy efficiency of the machine; the pressure shocks within hydraulic actuators is decreased as well, thus the stationarity of the whole machine is improved accordingly.