阀芯

阀芯是先导阀内的关键滑动部件，通过在一个精密加工的孔内轴向移动来调节液压或气动流体的流量。其位置决定哪些端口被连接或阻断，从而实现对工业机械中执行器的方向控制。阀芯具有精密加工的台肩和沟槽，与阀体端口对齐，在受到先导压力、机械力或电信号驱动时形成特定的流道。

阀芯的工作原理是滑动原理，即阀芯在阀体内的轴向移动改变阀芯台肩/沟槽与阀体端口之间的对齐关系。当阀芯移动位置时，它要么连接要么阻断流体通道，将加压流体引导至特定端口，同时允许其他端口的回流。这种移动通常由阀芯两端的先导压力差控制，从而实现对流体流量的精确计量，用于方向控制应用。

The valve spool operates on the sliding principle where axial movement within the valve body changes the alignment between spool lands/grooves and valve ports. When the spool shifts position, it either connects or blocks fluid passages, directing pressurized fluid to specific ports while allowing return flow from others. This movement is typically controlled by pilot pressure differentials across the spool ends, creating precise metering of fluid flow for directional control applications.