升降货梯液压缸传动换向方法

升降货梯http://www.jntr168.com/系统中的换向方式和换向控制参数对换向冲击有决定性的作用，升降货梯采用液压传动，设计新的液压换向系统已迫在眉睫。

1、升降货梯采用行程换向阀的换向方法，换向阀芯上联出一拔杆，为采用行程换向阀换向，利用工作台上的行程挡块推动拔杆来实现自动换向。升降货梯的工作台慢速运动时，当换向阀到达中间位置，不管液压缸左右两腔或是都通压力油、或是都通回油、或是都封闭，这时，液压缸两腔没有液压力推动，都会使工作台运动停止，因而换向阀不能到达另一端，也就出现了所谓“死点”。
Cargo lifter using the commutation valve stroke, valve core linking the pull rod for the introduction of travel valve for the use of the bench trip block push pull lever for automatic commutation. Cargo lifter bench slow motion, when the valve reaches the intermediate position, regardless of the cylinder about two cavities or through pressure oil, or both through the oil return, or are closed, then, there is no two-chamber hydraulic cylinders hydraulic pressure pushes,will make table movement stops, thus reversing valve can not reach the other end, it appeared the so-called "dead spots."

2、升降货梯采用电磁换向阀的换向方法，由行程挡块推动行程开关发出换向信号，行程换向阀改为电磁换向阀的换向方法。使电磁铁动作推动滑阀换向，可以防止“死点”但它一种开关型液压阀，根据指令瞬间开启或闭合，即瞬时接通或切断回油通道，这样的液压换向系统在换向时会有很大的冲击发生。
Cargo lifter electromagnetic valve commutation method to promote the trip switch issued by the trip block commutation signals, stroke valve solenoid valve instead of commutation. Action to promote the spool so that the electromagnet

commutation, can prevent the "dead spots" but it kind of switching hydraulic valves, and instantly open or closed, the instantaneous switching on or off the oil return passage in accordance with instructions, so that the hydraulic reversing system change will be a great shock to happen when.

3、升降货梯http://www.jntr168.com/采用电液换向阀的换向方法，先导阀没有换向前，用电液换向阀替换电磁换向阀便构成了一种新的换向方法，电液换向阀由先导阀电磁滑阀和主阀液动滑阀组成。一旦控制油路切换了方向，升降货梯的主阀阀芯就依照事先调定的速度移动到另一工作位置，主油路方向改变，工作台也就换向运动，防止了换向“死点”。
Cargo lifter electro-hydraulic valve commutation method, the pilot did not change forward, electro-hydraulic valve solenoid valve replacement would constitute a new commutation method, electro-hydraulic valve by the pilot valve electromagnetic spool valve and the main valve hydraulic slide valve. Once the control circuit to switch the direction of the main valve spool cargo lifter on in accordance with the pre-set speed transfer work to another location, change the direction of the main oil line, the table will change to the campaign to prevent the change to "dead spots . "