如何使液压起重臂装卸木材时动作更快、更平稳,这一直是设计者们努力的一个重要目标。迄今为止,林业用起重臂通常都装有所谓开式系统,其中是由一个定量油泵将动力不断输送给一个所谓“中心开式”阀门装置。当控制起重臂的六种动作的六个控制杆都处於中立位置时,阀门 How to make the hydraulic boom move faster and more smoothly when loading and unloading wood has always been an important goal for designers. Until now, forestry booms have often been equipped with so-called open systems in which a constant oil pump delivers power to a so-called “central open” valve device. When the six levers controlling the six movements of the boom are all in the neutral position, the valve