電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是(shi)用電(dian)磁(ci)控(kong)制(zhi)的(de)工業設(she)備，是(shi)用來控(kong)制(zhi)流體的(de)自動(dong)化(hua)基礎元件，屬于執行器，并(bing)不限于液壓(ya)、氣(qi)動(dong)。用在工業控(kong)制(zhi)系統中調(diao)整介(jie)質的(de)方向(xiang)、流量、速(su)度和其他的(de)參數。電(dian)磁(ci)閥(fa)(fa)可以配合不同(tong)的(de)電(dian)路來實現預期的(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)精度和靈(ling)活(huo)性都(dou)能夠保證。電(dian)磁(ci)閥(fa)(fa)有很多種(zhong)，不同(tong)的(de)電(dian)磁(ci)閥(fa)(fa)在控(kong)制(zhi)系統的(de)不同(tong)位置發揮作用，最常用的(de)是(shi)單(dan)向(xiang)閥(fa)(fa)、安(an)全閥(fa)(fa)、方向(xiang)控(kong)制(zhi)閥(fa)(fa)、速(su)度調(diao)節閥(fa)(fa)等(deng)。

電磁(ci)(ci)閥(fa)里有密閉(bi)的(de)(de)腔，在不同(tong)位置開(kai)有通(tong)孔，每個(ge)孔連接不同(tong)的(de)(de)油管，腔中(zhong)間是活(huo)塞(sai)(sai)，兩面(mian)(mian)是兩塊電磁(ci)(ci)鐵，哪面(mian)(mian)的(de)(de)磁(ci)(ci)鐵線圈通(tong)電閥(fa)體(ti)(ti)就會被(bei)吸引(yin)到哪邊(bian)，通(tong)過(guo)控(kong)制閥(fa)體(ti)(ti)的(de)(de)移動(dong)來開(kai)啟或關閉(bi)不同(tong)的(de)(de)排(pai)油孔，而進(jin)油孔是常開(kai)的(de)(de)，液(ye)壓油就會進(jin)入(ru)不同(tong)的(de)(de)排(pai)油管，然后通(tong)過(guo)油的(de)(de)壓力來推動(dong)油缸的(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又(you)帶(dai)動(dong)活(huo)塞(sai)(sai)桿，活(huo)塞(sai)(sai)桿帶(dai)動(dong)機械(xie)裝置。這樣通(tong)過(guo)控(kong)制電磁(ci)(ci)鐵的(de)(de)電流通(tong)斷就控(kong)制了機械(xie)運(yun)動(dong)。

1、電(dian)磁閥從原理(li)上分為三大類：

直動式電(dian)磁(ci)閥

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

特點：在真空、負壓、零壓時能正常工作，但通徑一般不超(chao)過25mm。

分步直動式電(dian)磁閥

原理：它是一(yi)種直(zhi)動和先導(dao)式相結合的原理，當(dang)入(ru)口與出口沒有壓(ya)差(cha)(cha)(cha)時(shi)，通(tong)電(dian)后，電(dian)磁(ci)(ci)力(li)(li)直(zhi)接把(ba)先導(dao)小(xiao)(xiao)閥(fa)(fa)和主(zhu)閥(fa)(fa)關(guan)(guan)閉件(jian)依次向上(shang)提起，閥(fa)(fa)門(men)(men)打開。當(dang)入(ru)口與出口達到啟動壓(ya)差(cha)(cha)(cha)時(shi)，通(tong)電(dian)后，電(dian)磁(ci)(ci)力(li)(li)先導(dao)小(xiao)(xiao)閥(fa)(fa)，主(zhu)閥(fa)(fa)下腔壓(ya)力(li)(li)上(shang)升，上(shang)腔壓(ya)力(li)(li)下降，從而(er)利(li)用壓(ya)差(cha)(cha)(cha)把(ba)主(zhu)閥(fa)(fa)向上(shang)推開；斷(duan)電(dian)時(shi)，先導(dao)閥(fa)(fa)利(li)用彈簧力(li)(li)或介質壓(ya)力(li)(li)推動關(guan)(guan)閉件(jian)，向下移動，使閥(fa)(fa)門(men)(men)關(guan)(guan)閉。

特點：在零壓(ya)差或真空、高壓(ya)時亦(yi)能可(ke)*動(dong)作，但功率較大，要求必須水(shui)平安裝。

先導式電(dian)磁閥

原理(li)：通電(dian)時，電(dian)磁力(li)把(ba)(ba)先(xian)導孔打(da)開(kai)，上腔室(shi)壓(ya)(ya)(ya)力(li)迅速(su)下(xia)降(jiang)，在關(guan) 閉(bi)件(jian)周圍形成(cheng)上低下(xia)高(gao)的壓(ya)(ya)(ya)差，流體壓(ya)(ya)(ya)力(li)推動(dong)關(guan)閉(bi)件(jian)向(xiang)上移動(dong)，閥門(men)(men)打(da)開(kai)；斷(duan)電(dian)時，彈簧力(li)把(ba)(ba)先(xian)導孔關(guan)閉(bi)，入口壓(ya)(ya)(ya)力(li)通過(guo)旁通孔迅速(su)腔室(shi)在關(guan)閥件(jian)周圍形成(cheng)下(xia)低上高(gao)的壓(ya)(ya)(ya)差，流體壓(ya)(ya)(ya)力(li)推動(dong)關(guan)閉(bi)件(jian)向(xiang)下(xia)移動(dong)，關(guan)閉(bi)閥門(men)(men)。

特點(dian)：流(liu)體(ti)壓力范圍上限較高，可任意(yi)安裝（需定(ding)制）但(dan)必須滿足流(liu)體(ti)壓差(cha)條件(jian)。

2、電磁閥(fa)從閥(fa)結構和材料上的不同與原(yuan)理上的區別，分(fen)為六個分(fen)支小類：直動膜(mo)片(pian)結構、分(fen)步直動膜(mo)片(pian)結構、先(xian)導膜(mo)片(pian)結構、直動活塞(sai)結構、分(fen)步直動活塞(sai)結構、先(xian)導活塞(sai)結構。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按照功能分(fen)類：水用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常(chang)開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等。