電(dian)磁閥(fa)(fa)（Electromagnetic valve）是用電(dian)磁控(kong)制(zhi)的(de)(de)工業設備，是用來(lai)(lai)控(kong)制(zhi)流體的(de)(de)自(zi)動化基礎元件，屬于(yu)執行(xing)器，并不(bu)限于(yu)液壓、氣動。用在工業控(kong)制(zhi)系統中調整介質的(de)(de)方(fang)向、流量(liang)、速度和其他的(de)(de)參數。電(dian)磁閥(fa)(fa)可以(yi)配合不(bu)同的(de)(de)電(dian)路來(lai)(lai)實現預期的(de)(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)(de)精度和靈活性都能(neng)夠保證。電(dian)磁閥(fa)(fa)有很多種(zhong)，不(bu)同的(de)(de)電(dian)磁閥(fa)(fa)在控(kong)制(zhi)系統的(de)(de)不(bu)同位(wei)置發揮作用，最常用的(de)(de)是單向閥(fa)(fa)、安全閥(fa)(fa)、方(fang)向控(kong)制(zhi)閥(fa)(fa)、速度調節閥(fa)(fa)等。

電(dian)(dian)磁閥里有(you)密閉(bi)的(de)(de)腔，在不同(tong)位置開(kai)有(you)通(tong)(tong)孔，每(mei)個孔連接(jie)不同(tong)的(de)(de)油管，腔中間(jian)是活(huo)(huo)塞(sai)，兩(liang)面是兩(liang)塊電(dian)(dian)磁鐵，哪面的(de)(de)磁鐵線圈通(tong)(tong)電(dian)(dian)閥體就(jiu)會被吸引到哪邊，通(tong)(tong)過(guo)控制閥體的(de)(de)移(yi)動(dong)來開(kai)啟或關(guan)閉(bi)不同(tong)的(de)(de)排(pai)油孔，而進油孔是常開(kai)的(de)(de)，液壓(ya)油就(jiu)會進入不同(tong)的(de)(de)排(pai)油管，然(ran)后通(tong)(tong)過(guo)油的(de)(de)壓(ya)力來推動(dong)油缸的(de)(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又帶(dai)動(dong)活(huo)(huo)塞(sai)桿，活(huo)(huo)塞(sai)桿帶(dai)動(dong)機(ji)械(xie)裝置。這樣通(tong)(tong)過(guo)控制電(dian)(dian)磁鐵的(de)(de)電(dian)(dian)流(liu)通(tong)(tong)斷就(jiu)控制了(le)機(ji)械(xie)運動(dong)。

1、電(dian)磁閥(fa)從原(yuan)理(li)上分(fen)為(wei)三大類：

直動式電磁(ci)閥

原(yuan)理：通電時，電磁線圈產(chan)生電磁力(li)(li)把(ba)關(guan)(guan)閉件(jian)從閥(fa)(fa)座上(shang)提起(qi)，閥(fa)(fa)門(men)(men)打開；斷(duan)電時，電磁力(li)(li)消失，彈(dan)簧把(ba)關(guan)(guan)閉件(jian)壓在閥(fa)(fa)座上(shang)，閥(fa)(fa)門(men)(men)關(guan)(guan)閉。

特(te)點(dian)：在真(zhen)空、負壓(ya)、零壓(ya)時能(neng)正常(chang)工(gong)作，但通徑一(yi)般不超(chao)過25mm。

分步直動式電磁閥

原理(li)：它是一種直動和(he)先(xian)(xian)(xian)導式相結合的原理(li)，當入口(kou)與出(chu)口(kou)沒有(you)壓(ya)(ya)差時，通(tong)電后，電磁力直接把(ba)先(xian)(xian)(xian)導小(xiao)閥(fa)(fa)(fa)和(he)主(zhu)(zhu)閥(fa)(fa)(fa)關閉件依次向(xiang)上提起，閥(fa)(fa)(fa)門打開。當入口(kou)與出(chu)口(kou)達到啟動壓(ya)(ya)差時，通(tong)電后，電磁力先(xian)(xian)(xian)導小(xiao)閥(fa)(fa)(fa)，主(zhu)(zhu)閥(fa)(fa)(fa)下腔壓(ya)(ya)力上升，上腔壓(ya)(ya)力下降，從而(er)利(li)用壓(ya)(ya)差把(ba)主(zhu)(zhu)閥(fa)(fa)(fa)向(xiang)上推開；斷(duan)電時，先(xian)(xian)(xian)導閥(fa)(fa)(fa)利(li)用彈簧力或介質(zhi)壓(ya)(ya)力推動關閉件，向(xiang)下移動，使(shi)閥(fa)(fa)(fa)門關閉。

特點：在零(ling)壓差或真空、高壓時亦能可(ke)*動作(zuo)，但功(gong)率較大，要求必須水平安(an)裝。

先導式電磁閥

原理：通(tong)電(dian)(dian)時，電(dian)(dian)磁(ci)力(li)(li)把先導(dao)孔(kong)打開(kai)，上腔(qiang)室壓(ya)力(li)(li)迅速下(xia)(xia)降(jiang)，在關(guan) 閉(bi)件(jian)周圍形(xing)成上低下(xia)(xia)高的(de)(de)壓(ya)差，流體壓(ya)力(li)(li)推動關(guan)閉(bi)件(jian)向上移動，閥門打開(kai)；斷電(dian)(dian)時，彈簧(huang)力(li)(li)把先導(dao)孔(kong)關(guan)閉(bi)，入口壓(ya)力(li)(li)通(tong)過旁通(tong)孔(kong)迅速腔(qiang)室在關(guan)閥件(jian)周圍形(xing)成下(xia)(xia)低上高的(de)(de)壓(ya)差，流體壓(ya)力(li)(li)推動關(guan)閉(bi)件(jian)向下(xia)(xia)移動，關(guan)閉(bi)閥門。

特點：流體(ti)壓(ya)(ya)力范(fan)圍上限較高，可任意安裝（需定制）但必須滿足流體(ti)壓(ya)(ya)差條(tiao)件。

2、電磁閥(fa)從閥(fa)結(jie)(jie)(jie)構(gou)和(he)材料上的不(bu)同與原(yuan)理上的區(qu)別，分(fen)為六(liu)個分(fen)支小類：直(zhi)動(dong)膜片結(jie)(jie)(jie)構(gou)、分(fen)步直(zhi)動(dong)膜片結(jie)(jie)(jie)構(gou)、先導膜片結(jie)(jie)(jie)構(gou)、直(zhi)動(dong)活塞(sai)結(jie)(jie)(jie)構(gou)、分(fen)步直(zhi)動(dong)活塞(sai)結(jie)(jie)(jie)構(gou)、先導活塞(sai)結(jie)(jie)(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按照(zhao)功能(neng)分(fen)類(lei)：水用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸(zheng)汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃(ran)氣(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氣(qi)體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微(wei)型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等。