電(dian)磁(ci)(ci)閥(fa)（Electromagnetic valve）是用(yong)(yong)電(dian)磁(ci)(ci)控制(zhi)的(de)(de)(de)工(gong)(gong)業設備(bei)，是用(yong)(yong)來控制(zhi)流體(ti)的(de)(de)(de)自動(dong)化基礎元(yuan)件，屬于執行器，并不限于液壓、氣動(dong)。用(yong)(yong)在工(gong)(gong)業控制(zhi)系(xi)統中調(diao)整介(jie)質的(de)(de)(de)方向(xiang)、流量、速度和其他的(de)(de)(de)參(can)數(shu)。電(dian)磁(ci)(ci)閥(fa)可以配(pei)合不同(tong)的(de)(de)(de)電(dian)路來實現(xian)預(yu)期的(de)(de)(de)控制(zhi)，而(er)控制(zhi)的(de)(de)(de)精度和靈(ling)活(huo)性(xing)都能夠保證。電(dian)磁(ci)(ci)閥(fa)有很多種，不同(tong)的(de)(de)(de)電(dian)磁(ci)(ci)閥(fa)在控制(zhi)系(xi)統的(de)(de)(de)不同(tong)位置發(fa)揮(hui)作用(yong)(yong)，最(zui)常(chang)用(yong)(yong)的(de)(de)(de)是單向(xiang)閥(fa)、安全閥(fa)、方向(xiang)控制(zhi)閥(fa)、速度調(diao)節閥(fa)等(deng)。

電磁閥里有(you)密閉的(de)(de)(de)腔，在不(bu)(bu)同(tong)位置開有(you)通(tong)(tong)孔(kong)，每個(ge)孔(kong)連接不(bu)(bu)同(tong)的(de)(de)(de)油(you)(you)(you)管，腔中間是(shi)活(huo)(huo)塞(sai)，兩面是(shi)兩塊電磁鐵，哪面的(de)(de)(de)磁鐵線圈通(tong)(tong)電閥體(ti)就會被(bei)吸引到(dao)哪邊(bian)，通(tong)(tong)過(guo)控(kong)(kong)(kong)制閥體(ti)的(de)(de)(de)移動(dong)來(lai)開啟或(huo)關閉不(bu)(bu)同(tong)的(de)(de)(de)排(pai)油(you)(you)(you)孔(kong)，而進(jin)油(you)(you)(you)孔(kong)是(shi)常(chang)開的(de)(de)(de)，液壓(ya)油(you)(you)(you)就會進(jin)入不(bu)(bu)同(tong)的(de)(de)(de)排(pai)油(you)(you)(you)管，然后通(tong)(tong)過(guo)油(you)(you)(you)的(de)(de)(de)壓(ya)力來(lai)推動(dong)油(you)(you)(you)缸的(de)(de)(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又(you)帶動(dong)活(huo)(huo)塞(sai)桿，活(huo)(huo)塞(sai)桿帶動(dong)機械裝置。這樣通(tong)(tong)過(guo)控(kong)(kong)(kong)制電磁鐵的(de)(de)(de)電流通(tong)(tong)斷(duan)就控(kong)(kong)(kong)制了機械運動(dong)。

1、電磁閥(fa)從原理(li)上(shang)分為三大類：

直動(dong)式電磁(ci)閥

原理：通電(dian)時(shi)，電(dian)磁(ci)(ci)線圈產生電(dian)磁(ci)(ci)力把關(guan)閉件從閥(fa)(fa)座上(shang)提起，閥(fa)(fa)門(men)打開；斷電(dian)時(shi)，電(dian)磁(ci)(ci)力消失，彈簧把關(guan)閉件壓(ya)在閥(fa)(fa)座上(shang)，閥(fa)(fa)門(men)關(guan)閉。

特(te)點：在(zai)真空、負壓、零壓時(shi)能正常工作，但通徑一般不超過25mm。

分步(bu)直動式電磁閥

原理：它是一種直動和先(xian)導(dao)式(shi)相結合的原理，當入口(kou)(kou)與出口(kou)(kou)沒有壓(ya)(ya)差時，通電(dian)(dian)后(hou)，電(dian)(dian)磁(ci)力直接把先(xian)導(dao)小閥(fa)(fa)和主(zhu)閥(fa)(fa)關(guan)閉件依(yi)次向上(shang)提起(qi)，閥(fa)(fa)門打開。當入口(kou)(kou)與出口(kou)(kou)達到啟動壓(ya)(ya)差時，通電(dian)(dian)后(hou)，電(dian)(dian)磁(ci)力先(xian)導(dao)小閥(fa)(fa)，主(zhu)閥(fa)(fa)下腔(qiang)壓(ya)(ya)力上(shang)升，上(shang)腔(qiang)壓(ya)(ya)力下降，從而利(li)用壓(ya)(ya)差把主(zhu)閥(fa)(fa)向上(shang)推開；斷電(dian)(dian)時，先(xian)導(dao)閥(fa)(fa)利(li)用彈(dan)簧力或介質壓(ya)(ya)力推動關(guan)閉件，向下移動，使(shi)閥(fa)(fa)門關(guan)閉。

特點：在零壓(ya)差(cha)或(huo)真空(kong)、高壓(ya)時亦能可*動作，但(dan)功率(lv)較大(da)，要(yao)求(qiu)必須水平安裝(zhuang)。

先導式電磁閥

原理：通(tong)(tong)電時，電磁力(li)(li)(li)把(ba)先(xian)導孔打(da)開(kai)，上(shang)腔室壓力(li)(li)(li)迅速下(xia)(xia)降，在(zai)關(guan) 閉件周圍形成上(shang)低(di)下(xia)(xia)高(gao)的壓差，流體(ti)壓力(li)(li)(li)推動關(guan)閉件向上(shang)移動，閥(fa)門(men)打(da)開(kai)；斷(duan)電時，彈簧力(li)(li)(li)把(ba)先(xian)導孔關(guan)閉，入口壓力(li)(li)(li)通(tong)(tong)過旁通(tong)(tong)孔迅速腔室在(zai)關(guan)閥(fa)件周圍形成下(xia)(xia)低(di)上(shang)高(gao)的壓差，流體(ti)壓力(li)(li)(li)推動關(guan)閉件向下(xia)(xia)移動，關(guan)閉閥(fa)門(men)。

特點：流體壓力范圍上限較高(gao)，可任(ren)意(yi)安(an)裝（需(xu)定制）但必須滿足流體壓差條(tiao)件。

2、電(dian)磁閥從閥結(jie)(jie)構和材料上的不同與原理上的區別(bie)，分(fen)為六(liu)個分(fen)支小類：直(zhi)動(dong)膜(mo)片結(jie)(jie)構、分(fen)步直(zhi)動(dong)膜(mo)片結(jie)(jie)構、先導膜(mo)片結(jie)(jie)構、直(zhi)動(dong)活(huo)塞(sai)(sai)結(jie)(jie)構、分(fen)步直(zhi)動(dong)活(huo)塞(sai)(sai)結(jie)(jie)構、先導活(huo)塞(sai)(sai)結(jie)(jie)構。

3、電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)按照(zhao)功能分(fen)類：水用(yong)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、燃氣(qi)(qi)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、消防(fang)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、氣(qi)(qi)體(ti)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、液體(ti)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、脈(mo)沖(chong)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、油(you)用(yong)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)、防(fang)爆電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)等。