電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是用(yong)(yong)電(dian)磁(ci)控(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)工業設備，是用(yong)(yong)來(lai)控(kong)(kong)(kong)制(zhi)(zhi)流體的(de)(de)自動化基礎(chu)元(yuan)件，屬(shu)于執行(xing)器，并不(bu)(bu)限于液(ye)壓、氣(qi)動。用(yong)(yong)在工業控(kong)(kong)(kong)制(zhi)(zhi)系統中調(diao)整介質的(de)(de)方向、流量、速度和其他的(de)(de)參數。電(dian)磁(ci)閥(fa)(fa)可(ke)以配(pei)合不(bu)(bu)同的(de)(de)電(dian)路來(lai)實(shi)現預期的(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)精度和靈(ling)活(huo)性都(dou)能夠保證(zheng)。電(dian)磁(ci)閥(fa)(fa)有很(hen)多種，不(bu)(bu)同的(de)(de)電(dian)磁(ci)閥(fa)(fa)在控(kong)(kong)(kong)制(zhi)(zhi)系統的(de)(de)不(bu)(bu)同位置發揮作用(yong)(yong)，最常用(yong)(yong)的(de)(de)是單(dan)向閥(fa)(fa)、安全閥(fa)(fa)、方向控(kong)(kong)(kong)制(zhi)(zhi)閥(fa)(fa)、速度調(diao)節(jie)閥(fa)(fa)等。

電(dian)磁(ci)(ci)閥(fa)里有密閉的(de)(de)腔(qiang)(qiang)，在不同位置開有通(tong)孔，每個孔連接(jie)不同的(de)(de)油(you)管，腔(qiang)(qiang)中間是活(huo)塞(sai)(sai)(sai)，兩面是兩塊電(dian)磁(ci)(ci)鐵(tie)，哪面的(de)(de)磁(ci)(ci)鐵(tie)線圈(quan)通(tong)電(dian)閥(fa)體就會被吸引到(dao)哪邊，通(tong)過(guo)控(kong)制(zhi)閥(fa)體的(de)(de)移動(dong)來(lai)開啟或關(guan)閉不同的(de)(de)排(pai)油(you)孔，而進(jin)油(you)孔是常開的(de)(de)，液壓(ya)油(you)就會進(jin)入不同的(de)(de)排(pai)油(you)管，然后通(tong)過(guo)油(you)的(de)(de)壓(ya)力來(lai)推動(dong)油(you)缸(gang)的(de)(de)活(huo)塞(sai)(sai)(sai)，活(huo)塞(sai)(sai)(sai)又帶動(dong)活(huo)塞(sai)(sai)(sai)桿，活(huo)塞(sai)(sai)(sai)桿帶動(dong)機(ji)械裝置。這(zhe)樣通(tong)過(guo)控(kong)制(zhi)電(dian)磁(ci)(ci)鐵(tie)的(de)(de)電(dian)流通(tong)斷就控(kong)制(zhi)了機(ji)械運動(dong)。

1、電磁閥(fa)從原理上分為三大類：

直(zhi)動式電磁閥

原理：通(tong)電(dian)(dian)時，電(dian)(dian)磁線圈產生電(dian)(dian)磁力把關(guan)閉件從閥(fa)(fa)座(zuo)(zuo)上提起，閥(fa)(fa)門(men)打開；斷電(dian)(dian)時，電(dian)(dian)磁力消(xiao)失，彈簧把關(guan)閉件壓(ya)在閥(fa)(fa)座(zuo)(zuo)上，閥(fa)(fa)門(men)關(guan)閉。

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

分步直動式電(dian)磁閥

原理：它是一種直(zhi)動(dong)和(he)先導式相(xiang)結合的原理，當(dang)(dang)入口(kou)與出(chu)(chu)口(kou)沒(mei)有壓(ya)差時(shi)(shi)，通(tong)電(dian)(dian)(dian)后(hou)(hou)，電(dian)(dian)(dian)磁(ci)(ci)力(li)(li)直(zhi)接把(ba)先導小閥(fa)(fa)和(he)主閥(fa)(fa)關(guan)閉(bi)件依(yi)次向上提起，閥(fa)(fa)門(men)打開。當(dang)(dang)入口(kou)與出(chu)(chu)口(kou)達到啟動(dong)壓(ya)差時(shi)(shi)，通(tong)電(dian)(dian)(dian)后(hou)(hou)，電(dian)(dian)(dian)磁(ci)(ci)力(li)(li)先導小閥(fa)(fa)，主閥(fa)(fa)下(xia)腔壓(ya)力(li)(li)上升，上腔壓(ya)力(li)(li)下(xia)降，從而利用壓(ya)差把(ba)主閥(fa)(fa)向上推開；斷電(dian)(dian)(dian)時(shi)(shi)，先導閥(fa)(fa)利用彈簧力(li)(li)或介(jie)質壓(ya)力(li)(li)推動(dong)關(guan)閉(bi)件，向下(xia)移動(dong)，使閥(fa)(fa)門(men)關(guan)閉(bi)。

特(te)點：在(zai)零壓差或真空(kong)、高壓時亦能可*動作，但功(gong)率較大，要求必須(xu)水平(ping)安裝。

先導式電磁閥

原理：通電時，電磁力把先導孔(kong)打開(kai)，上(shang)(shang)腔(qiang)室壓力迅速下(xia)降，在關 閉(bi)(bi)(bi)件(jian)周(zhou)(zhou)圍形成上(shang)(shang)低下(xia)高的(de)壓差，流體壓力推(tui)動(dong)(dong)(dong)關閉(bi)(bi)(bi)件(jian)向(xiang)上(shang)(shang)移(yi)動(dong)(dong)(dong)，閥門打開(kai)；斷電時，彈簧力把先導孔(kong)關閉(bi)(bi)(bi)，入口壓力通過旁(pang)通孔(kong)迅速腔(qiang)室在關閥件(jian)周(zhou)(zhou)圍形成下(xia)低上(shang)(shang)高的(de)壓差，流體壓力推(tui)動(dong)(dong)(dong)關閉(bi)(bi)(bi)件(jian)向(xiang)下(xia)移(yi)動(dong)(dong)(dong)，關閉(bi)(bi)(bi)閥門。

特點：流體壓力(li)范圍上(shang)限(xian)較高，可任意(yi)安(an)裝（需定制）但(dan)必須滿足流體壓差條(tiao)件。

2、電(dian)磁閥(fa)從(cong)閥(fa)結(jie)構(gou)(gou)和(he)材料(liao)上(shang)的不同與原理(li)上(shang)的區別，分為六個(ge)分支(zhi)小類：直動膜(mo)(mo)片(pian)結(jie)構(gou)(gou)、分步直動膜(mo)(mo)片(pian)結(jie)構(gou)(gou)、先導膜(mo)(mo)片(pian)結(jie)構(gou)(gou)、直動活(huo)(huo)塞(sai)結(jie)構(gou)(gou)、分步直動活(huo)(huo)塞(sai)結(jie)構(gou)(gou)、先導活(huo)(huo)塞(sai)結(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按照功能分類：水用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃(ran)氣(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、消防(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氣(qi)體電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微(wei)(wei)型電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa) 常開(kai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、直流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防(fang)(fang)爆電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等。