升降货梯顺序阀有哪些作用？

升降货梯http://www.jntr168.com/采用了液压系统为主要的动力单元，进行正常的升降运行。当升降货梯液压系统中有两个以上的执行机构时，为使两个执行机构按一定顺序动作，便需采用顺序阀。
Cargo lifter with a hydraulic system as the main power unit, normal lift operation. When cargo lifter hydraulic system has two or more actuators, in order to make the two actuators according to certain sequence of actions, it requires the use of sequential valve.
 
升降货梯工作机构的顺序动作可采用多种控制方式来实现，如机械的、电气的及液压的等，顺序阀是采用液压方式进行顺序动作控制的阀类。升降货梯顺序阀也有直动式和导阀控制式两种，其结构和工作原理与滋流阀、安全阀相似。进口油压通过阀芯上的轴向孔引至阀芯底部，和调定的弹簧力相平衡。进口油压低于弹簧调定压力时，阀芯切断进出油路，当进口油压高于弹簧调定压力时，阀芯抬起，进出油路接通。升降货梯的顺序阀密封性要求较高，滑阀的封油长度较长，以避免因泄漏而影响升降货梯机构顺序动作的可靠性。顺序阀的排油口为工作油压，因此弹簧腔的泄油管应直接引回油箱，而不能象滋流阀那样在阀内和回油口相接。升降货梯的结构与滋流阀职能符号的差别是有单独的泄油口，出口是二次压力油路，不接油箱。
Cargo lifter working bodies of the sequence of actions can be used to implement a variety of control methods, such as mechanical, electrical and hydraulic, etc., sequence valve is hydraulically sequential operation control valves. Cargo lifter sequence valve also has direct-acting and pilot-type two, the structure and works with AIDS valve, safety valve similar. Import oil through the axial hole lead on the spool to the bottom of the valve body, and it is set spring force equilibrium. Import oil pressure falls below the set pressure of the spring, the spool cutting out the oil, imported oil is higher than the spring when a set pressure, the valve lift, turned out the oil. Higher cargo lifter sequence valve sealing requirements, longer length of seal oil slide valve in order to avoid leakage and cargo lift mechanism sequence of actions affecting reliability. Sequence valve discharge port of the working oil pressure, and therefore the spring chamber drain line should be drawn directly back to the tank, but did not like mayonnaise valve in the valve and back to the oil port phase. Differences in the structure and function symbols AIDS valve cargo lift is a separate drain port, export is secondary pressure oil passage, do not take the tank.
 
升降货梯http://www.jntr168.com/为顺序阀的一种应用方法，油缸1驱动钻头钻削完毕退回终点后，油路压力升高，顺序阀打开，于是油缸动作，驱动刀具进行切断。
The latter application methods cargo lift to order valve cylinder driving drill drilling is completed to return the end, the oil pressure increases, the sequence valve opens, so the cylinder moves, drive for cutting tools.