掘进机负荷传感液压系统优缺点的研究分析

Research and Analysis of Advantages and Disadvantages of Road-header Load Sensing Hydraulic System

负荷传感液压系统在国内外已普遍应用于掘进机,通过对负荷传感液压系统工作原理的分析得知：（1）因为它有高度系统集成,将系统所需的控制功能集成在1~2个元件内,为机器安装布置节约大量空间;（2）负荷传感系统可根据负载的变化,对泵流量作相应的调节,使换向阀节流点前后的压差保持不变,即泵的压力总是等于负荷压力与此节流压差之和,使泵流量始终与换向阀上调节的流量需求相适应。因此,负荷传感系统不受负载变化的影响,调速刚度大为提高;（3）因为它相对常规定量泵和变量泵调速系统可以实现按需供油,系统始终没有多余流量,彻底消除系统溢流损失,但不能消除系统节流损失、沿程损失和局部损失,另外它要实现单泵驱动多个执行机构同时工作、互不干扰,又会给系统带来新的压力补偿损失,这也是负荷传感液压系统的最大缺点。

At present the load sensing home and abroad generally. Through hydraulic system has been applied to the road-header both at the analysis of working principles of load sensing hydraulic system, it can be concluded that： Firstly, the road-header sensing hydraulic system has a highly system integration, so it can integrate control required by the system within 1 to 2 components so as to save large amount of space for machine installation; Secondly, the load sensing hydraulic system can make adjustment to the pump flow according to load changes so as to make the pressure differential around the throttling point at reversing valves remain unchanged, namely the pump pressure always equals to the sum of load pressure and the throttle pressure difference, so it can make pump flow adapts to the flow required by the reversing valves accordingly. Therefore, load sensing hydraulic system is not influenced by the change of load, and speed stiffness will be improved greatly;Thirdly, comparing with conventional quantitative pump and the variable pump speed regulation system, it can realize on-demand supply. The system always has no spare flow, so it can eliminate system overflow loss, but not loss of throttling, along the riser system loss and partial loss. In addition, if it is going to realize single pump driven and many enforcement to system for Key words： agencies working at the same time without interfering each other, it will bring new pressure the compensation of losses, which is the largest disadvantage of the system.