电磁阀的定义：电磁阀(Electromagnetic valve)是用电磁控制的工业设备，是用来控制流体的自动化基础元件，属于执行器，并不限于液压、气动。用在工业控制系统中调整介质的方向、流量、速度和其他的参数。电磁阀可以配合不同的电路来实现预期的控制，而控制的精度和灵活性都能够保证。电磁阀有很多种，不同的电磁阀在控制系统的不同位置发挥作用，zui常用的是单向阀、安全阀、方向控制阀、速度调节阀等。The definition of solenoid valve: the Electromagnetic valve is an industrial equipment controlled by Electromagnetic control. It is an automatic basic component used to control the fluid. It belongs to the actuator and is not limited to hydraulic and pneumatic. Adjust the direction, flow, speed and other parameters of the medium in an industrial control system. The solenoid valve can cooperate with different circuits to achieve the expected control, and the control precision and flexibility can be guaranteed. There are many kinds of solenoid valves. Different solenoid valves play a role in different positions in the control system. The most common ones are one-way valve, safety valve, directional control valve, speed regulating valve and so on.

电磁阀的原理：电磁阀里有密闭的腔，在不同位置开有通孔，每个孔连接不同的油管，腔中间是活塞，两面是两块电磁铁，哪面的磁铁线圈通电阀体就会被吸引到哪边，通过控制阀体的移动来开启或关闭不同的排油孔，而进油孔是常开的，液压油就会进入不同的排油管，然后通过油的压力来推动油缸的活塞，活塞又带动活塞杆，活塞杆带动机械装置。这样通过控制电磁铁的电流通断就控制了机械运动。The principle of electromagnetic valve, solenoid valve has closed cavity, in a different location to open a hole, each hole to connect different tubing, cavity piston is among, both sides are two electromagnets, which face the magnet coil electricity body which side will be attracted to, through to control the movement of the valve to open or close the different discharge of oil hole, and the oil hole is always open, hydraulic fluid will enter the different oil drain, and then through the oil pressure to push the cylinder piston, piston drives the piston rod, piston rod drive mechanism. This controls the mechanical movement by controlling the electrical current of the electromagnet.

电磁阀的分类：

大体有两种：
1.电磁阀：采用分步直接式结构，使电磁力直接作用到主阀芯，在压差等于零或真空时，亦能可靠动作，阀芯磨损能自动补偿，大大地延长了使用寿命，低功耗，无泄漏，适用于制冷剂、蒸气、水、空气、油、真空等介质。
2. 特种电磁阀：超低温电磁阀（适用于－196℃液氮）、高温电磁阀（zui高温度可达450℃）、防爆电磁阀（得把适用于易爆易燃的危险环境）、塑料王电磁阀（特别适用于酸碱、超净流体介质）、信号电磁阀、常开电磁阀、单向电磁阀、带手动电磁阀等。

简单来讲
所有的电磁阀都是将电信号转成气的动作（就是信号的转换）

Classification of solenoid valves:

There are two general types:

1. Electromagnetic valve: the direct structure step by step, the electromagnetic force directly to the main valve core, the differential pressure is equal to zero or vacuum, can reliable action, the valve core can automatically compensate the wear and greatly prolong the service life, low power consumption, no leakage, applicable to the refrigerant, steam, water, air, oil, vacuum, etc.

2. Special solenoid valve: cryogenic solenoid valve (applicable to - 196 ℃, liquid nitrogen), high-temperature solenoid valve (the highest temperature can reach 450 ℃), explosion-proof solenoid valve (have to apply to explosive flammable dangerous environment), plastic king solenoid valve (especially suitable for acid and alkali, super clean fluid), signal solenoid valve, normally open solenoid valve, a one-way electromagnetic valve, electromagnetic valve with manual, etc.

simply

All solenoid valves are the act of converting electrical signals into gas (the signal conversion).