電(dian)磁(ci)閥(fa)（Electromagnetic valve）是用電(dian)磁(ci)控(kong)(kong)(kong)制(zhi)的(de)工業設備，是用來控(kong)(kong)(kong)制(zhi)流(liu)體的(de)自動化基礎元件，屬(shu)于執(zhi)行器(qi)，并不(bu)(bu)限于液壓(ya)、氣動。用在工業控(kong)(kong)(kong)制(zhi)系(xi)統中調(diao)(diao)整介質的(de)方向、流(liu)量、速度(du)和其他(ta)的(de)參數(shu)。電(dian)磁(ci)閥(fa)可以配合不(bu)(bu)同的(de)電(dian)路來實現(xian)預期的(de)控(kong)(kong)(kong)制(zhi)，而控(kong)(kong)(kong)制(zhi)的(de)精度(du)和靈(ling)活性(xing)都能夠保證。電(dian)磁(ci)閥(fa)有很多種，不(bu)(bu)同的(de)電(dian)磁(ci)閥(fa)在控(kong)(kong)(kong)制(zhi)系(xi)統的(de)不(bu)(bu)同位置(zhi)發揮作用，最常用的(de)是單向閥(fa)、安全閥(fa)、方向控(kong)(kong)(kong)制(zhi)閥(fa)、速度(du)調(diao)(diao)節閥(fa)等。

電(dian)磁(ci)閥里有(you)密閉的(de)腔(qiang)，在不(bu)同(tong)位置開有(you)通(tong)孔，每個孔連(lian)接(jie)不(bu)同(tong)的(de)油(you)(you)(you)管(guan)，腔(qiang)中(zhong)間是活(huo)(huo)塞，兩面是兩塊(kuai)電(dian)磁(ci)鐵，哪(na)面的(de)磁(ci)鐵線(xian)圈通(tong)電(dian)閥體就會(hui)被吸引到哪(na)邊，通(tong)過控制閥體的(de)移(yi)動來(lai)開啟(qi)或(huo)關閉不(bu)同(tong)的(de)排(pai)油(you)(you)(you)孔，而(er)進油(you)(you)(you)孔是常(chang)開的(de)，液壓油(you)(you)(you)就會(hui)進入不(bu)同(tong)的(de)排(pai)油(you)(you)(you)管(guan)，然(ran)后通(tong)過油(you)(you)(you)的(de)壓力來(lai)推動油(you)(you)(you)缸的(de)活(huo)(huo)塞，活(huo)(huo)塞又帶(dai)動活(huo)(huo)塞桿，活(huo)(huo)塞桿帶(dai)動機(ji)械裝置。這樣通(tong)過控制電(dian)磁(ci)鐵的(de)電(dian)流通(tong)斷就控制了(le)機(ji)械運(yun)動。

1、電(dian)磁閥從(cong)原理上分為三大類：

直動式電磁閥

原理(li)：通電(dian)(dian)時(shi)(shi)，電(dian)(dian)磁線(xian)圈產生(sheng)電(dian)(dian)磁力(li)把(ba)(ba)關閉件從閥座(zuo)上(shang)提(ti)起，閥門打(da)開；斷電(dian)(dian)時(shi)(shi)，電(dian)(dian)磁力(li)消(xiao)失，彈(dan)簧把(ba)(ba)關閉件壓在(zai)閥座(zuo)上(shang)，閥門關閉。

特點：在真(zhen)空、負壓(ya)、零壓(ya)時能正常工作，但通徑(jing)一般(ban)不超(chao)過25mm。

分(fen)步(bu)直動式(shi)電磁閥

原理(li)：它是一種(zhong)直動和(he)先(xian)(xian)導(dao)式(shi)相結合的原理(li)，當入口與(yu)出(chu)口沒有壓(ya)(ya)差時，通(tong)電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)直接把(ba)先(xian)(xian)導(dao)小(xiao)閥(fa)(fa)(fa)和(he)主(zhu)閥(fa)(fa)(fa)關閉(bi)件(jian)依次向上(shang)提起，閥(fa)(fa)(fa)門(men)打(da)開。當入口與(yu)出(chu)口達到啟動壓(ya)(ya)差時，通(tong)電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)先(xian)(xian)導(dao)小(xiao)閥(fa)(fa)(fa)，主(zhu)閥(fa)(fa)(fa)下腔(qiang)壓(ya)(ya)力(li)上(shang)升，上(shang)腔(qiang)壓(ya)(ya)力(li)下降(jiang)，從而利用壓(ya)(ya)差把(ba)主(zhu)閥(fa)(fa)(fa)向上(shang)推開；斷電(dian)(dian)時，先(xian)(xian)導(dao)閥(fa)(fa)(fa)利用彈簧力(li)或介質壓(ya)(ya)力(li)推動關閉(bi)件(jian)，向下移動，使閥(fa)(fa)(fa)門(men)關閉(bi)。

特點：在(zai)零壓差或真(zhen)空、高壓時亦能可*動作(zuo)，但功率較大，要求必須水平安(an)裝。

先(xian)導式電磁閥(fa)

原理：通(tong)(tong)電時(shi)，電磁力把先(xian)導(dao)孔打開，上(shang)(shang)腔(qiang)室壓(ya)力迅速下(xia)(xia)(xia)降(jiang)，在關 閉(bi)(bi)件(jian)(jian)周圍形成(cheng)上(shang)(shang)低(di)下(xia)(xia)(xia)高的(de)壓(ya)差(cha)，流體壓(ya)力推動關閉(bi)(bi)件(jian)(jian)向(xiang)上(shang)(shang)移(yi)動，閥門(men)打開；斷電時(shi)，彈簧力把先(xian)導(dao)孔關閉(bi)(bi)，入口壓(ya)力通(tong)(tong)過旁通(tong)(tong)孔迅速腔(qiang)室在關閥件(jian)(jian)周圍形成(cheng)下(xia)(xia)(xia)低(di)上(shang)(shang)高的(de)壓(ya)差(cha)，流體壓(ya)力推動關閉(bi)(bi)件(jian)(jian)向(xiang)下(xia)(xia)(xia)移(yi)動，關閉(bi)(bi)閥門(men)。

特(te)點：流體壓力范圍上限較高，可任意(yi)安(an)裝(zhuang)（需(xu)定制）但必須(xu)滿(man)足(zu)流體壓差條件(jian)。

2、電磁閥從閥結(jie)(jie)構(gou)和材料上的不同與原理上的區別(bie)，分(fen)(fen)為六個分(fen)(fen)支小類：直動膜(mo)片(pian)結(jie)(jie)構(gou)、分(fen)(fen)步直動膜(mo)片(pian)結(jie)(jie)構(gou)、先(xian)導膜(mo)片(pian)結(jie)(jie)構(gou)、直動活塞(sai)結(jie)(jie)構(gou)、分(fen)(fen)步直動活塞(sai)結(jie)(jie)構(gou)、先(xian)導活塞(sai)結(jie)(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)按照功能分類：水(shui)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、蒸汽(qi)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)(ye)體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)(ye)壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa) 常開(kai)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、高壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)等。