负载敏感液压系统压力冲击原因与抑制方法  

Pressure Impact Causes and Suppression Methods in Load-sensing Hydraulic System

作　　者：顾海荣[1] 张小环 徐信芯[1,2] PAN Min 朱文锋 GU Hai-rong;ZHANG Xiao-huan;XU Xin-xin;PAN Min;ZHU Wen-feng(National Engineering Laboratory for Highway Maintenance Equipment,Chang'an University,Xi'an 710064,Shaanxi,China;Henan Gaoyuan Maintenance Technology Limited Company,Xinxiang 453000,Henan,China;Department of Mechanical Engineering,University of Bath,Bath BA27AY,Avon,UK)

机构地区：[1]长安大学公路养护装备国家工程实验室,陕西西安710064 [2]河南省高远公路养护技术有限公司,河南新乡453000 [3]巴斯大学机械工程学院,埃文巴斯BA27AY

出　　处：《中国公路学报》2021年第5期237-246,共10页China Journal of Highway and Transport

基　　金：国家重点研发计划项目(2018YFC0808204);国家自然科学基金项目(51805041);河南省重大科技专项项目(191110211500)。

摘　　要：为了提高流量控制阀快速、频繁启闭的负载敏感液压系统的可靠性,建立了负载敏感泵与流量控制阀之间管路内的流量方程和压力方程,分析了引起负载敏感液压系统压力冲击的原因和影响冲击压力峰值的因素,提出在负载敏感泵与流量控制阀之间设置防冲击回路,以抑制负载敏感液压系统的压力冲击。基于AMESim软件建立了负载敏感液压系统的仿真模型,对比研究了液压元件的性能参数、液压系统参数和操作参数等对负载敏感液压系统冲击压力峰值的影响,以及防冲击回路对于抑制负载敏感液压系统压力冲击的作用。研制了负载敏感液压系统试验台,对理论研究和仿真结果的正确性进行了验证。研究结果表明:负载敏感泵出口流量变化滞后于流量控制阀流量的变化,导致泵阀之间管路内的净流量增加,此为流量控制阀突然关闭时负载敏感泵与流量控制阀之间管路内形成压力冲击的诱因;负载敏感泵初始工作排量越大、流量控制阀关闭速度越快,负载敏感液压系统冲击压力的峰值越高;在负载敏感泵出口处设置防冲击回路,通过负载敏感系统的反馈压力与负载敏感泵出口压力之间的差值以控制防冲击回路中卸荷阀的启闭,减小泵阀之间管路内净流量的增加量,能够显著抑制负载敏感液压系统压力冲击的峰值;负载敏感泵初始工作排量较大的情况下,防冲击回路可以降低冲击压力峰值68%以上。In this study, flow and pressure equations for a pipeline between a load-sensing(LS) pump and a flow control valve(FCV) were derived to improve the reliability of the LS hydraulic system with an FCV closing rapidly and frequently. The cause of pressure impact on the LS hydraulic system was analyzed, and the influence factors on the peak value of the impact pressure were evaluated. An antishock loop was set between the FCV and the LS pump to suppress the pressure effect. A simulation model of the LS hydraulic system was established in AMESim software. The factors influencing the peak value of the impact pressure on the LS hydraulic system, such as the hydraulic component performance, hydraulic system parameters, and operational parameters, were compared and analyzed. In addition, simulations were performed to investigate the effect of the antishock loop on the pressure impact on the LS hydraulic system. An LS hydraulic system test rig was developed, and the theoretical analysis and simulation results were verified. The results show that the variation in the LS pump discharge flow lags the FCV flow. This lag increases the net flow in the pipeline between the LS pump and FCV when the FCV is closed suddenly, inducing pressure impact. The larger the initial LS pump displacement or the faster the FCV closing speed, the higher the peak value of impact pressure on the LS hydraulic system. An antishock loop was set at the LS pump outlet. The opening or closing of the unloading valve was controlled by the difference between the LS and discharge pressures of the pump to reduce the net flow increase in the pipeline between the pump and the valve. This reduction can significantly restrain the peak value of impact pressure on the LS hydraulic system. The antishock loop reduces the peak value of impact pressure by more than 68% when the initial displacement of the LS pump is large.

关 键 词：机械工程 压力冲击抑制方法 仿真 负载敏感液压系统 试验 

分 类 号：U415.5[交通运输工程—道路与铁道工程]