进出口独立控制液压挖掘机回转系统运行特性*

传统液压挖掘机回转系统是由单自由度的四边联动的多路阀控制，导致其可控性较差，能耗较大。针对这一问题，提出采用泵阀复合、压力流量匹配的进出口独立的回路原理，控制液压挖掘机回转系统，液压马达两腔的压力和流量可以根据不同的工况进行独立调节。建立液压挖掘机回转系统机械结构多体动力学与电液系统联合的数字样机，利用该样机对所提出系统的可行性进行验证，针对回转系统大惯性的特点，分别对启动阶段和制动阶段制定相应的控制策略，仿真结果表明系统运行平稳。在此基础上，进一步构建基于上述原理的试验系统，并与LUDV系统试验结果进行对比，试验结果表明采用泵阀复合进出口独立控制方法能耗降低25.5%~35.6%，阀口压力损失减小50%，显著抑制上车摆动现象。

Excavator Swing System Controlled with Separate Meter-in and Meter-out Method

Conventional swing system of hydraulic excavator is controlled by a valve control system with single degree of freedom due to the fact that its inlet and outlet orifices are connected mechanically, as a consequence, it has some disadvantages such as bad controllability and high energy consumption. To solve this problem, a separate meter-in and meter-out hydraulic excavator swing system with pump and valve combined control and flow rate matching is proposed. In this system, the pressure and flow rate of the motor working chambers can be controlled independently according to the working condition. Furthermore, a virtual prototype is developed consisting of the hydraulic excavator mechanical structure with multi-body dynamics and electro-hydraulic system for analyzing the feasibility of this swing system, and the simulation result demonstrates that this system works smoothly. After using the presented control strategies, compared with the LUDV system, the result of the experiment shows that a reduced energy consumption of up to 25.5%-35.6% for the swing drive is achieved, the system can reduce the throttle loss 50% and suppress the swing vibration obviously.