電磁(ci)閥(fa)（Electromagnetic valve）是(shi)用電磁(ci)控(kong)制(zhi)的(de)(de)(de)工(gong)業設備，是(shi)用來(lai)控(kong)制(zhi)流體(ti)的(de)(de)(de)自(zi)動(dong)化(hua)基礎元件(jian)，屬于執行器，并不(bu)限于液(ye)壓、氣(qi)動(dong)。用在(zai)工(gong)業控(kong)制(zhi)系統中調(diao)整介質(zhi)的(de)(de)(de)方(fang)向(xiang)、流量(liang)、速(su)度(du)(du)和其他的(de)(de)(de)參數。電磁(ci)閥(fa)可以(yi)配合不(bu)同的(de)(de)(de)電路(lu)來(lai)實現預期的(de)(de)(de)控(kong)制(zhi)，而(er)控(kong)制(zhi)的(de)(de)(de)精度(du)(du)和靈活(huo)性都能夠保證。電磁(ci)閥(fa)有很多種，不(bu)同的(de)(de)(de)電磁(ci)閥(fa)在(zai)控(kong)制(zhi)系統的(de)(de)(de)不(bu)同位置發揮作用，最常用的(de)(de)(de)是(shi)單向(xiang)閥(fa)、安全閥(fa)、方(fang)向(xiang)控(kong)制(zhi)閥(fa)、速(su)度(du)(du)調(diao)節閥(fa)等。

電(dian)(dian)磁閥里有密閉的(de)(de)腔(qiang)，在不(bu)(bu)(bu)同(tong)(tong)位置(zhi)開(kai)有通(tong)(tong)孔(kong)(kong)(kong)，每個孔(kong)(kong)(kong)連接不(bu)(bu)(bu)同(tong)(tong)的(de)(de)油(you)(you)管，腔(qiang)中間是活(huo)塞(sai)(sai)，兩(liang)面是兩(liang)塊電(dian)(dian)磁鐵(tie)，哪面的(de)(de)磁鐵(tie)線(xian)圈通(tong)(tong)電(dian)(dian)閥體就會被吸引到哪邊，通(tong)(tong)過(guo)控(kong)制(zhi)閥體的(de)(de)移動(dong)來(lai)開(kai)啟(qi)或關閉不(bu)(bu)(bu)同(tong)(tong)的(de)(de)排(pai)油(you)(you)孔(kong)(kong)(kong)，而進(jin)油(you)(you)孔(kong)(kong)(kong)是常開(kai)的(de)(de)，液壓(ya)油(you)(you)就會進(jin)入(ru)不(bu)(bu)(bu)同(tong)(tong)的(de)(de)排(pai)油(you)(you)管，然后(hou)通(tong)(tong)過(guo)油(you)(you)的(de)(de)壓(ya)力(li)來(lai)推動(dong)油(you)(you)缸的(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又帶(dai)動(dong)活(huo)塞(sai)(sai)桿(gan)(gan)，活(huo)塞(sai)(sai)桿(gan)(gan)帶(dai)動(dong)機械(xie)裝置(zhi)。這(zhe)樣通(tong)(tong)過(guo)控(kong)制(zhi)電(dian)(dian)磁鐵(tie)的(de)(de)電(dian)(dian)流通(tong)(tong)斷就控(kong)制(zhi)了機械(xie)運動(dong)。

1、電磁閥從原(yuan)理上分為三大類(lei)：

直動(dong)式電磁閥

原理(li)：通電時，電磁線圈產(chan)生電磁力把(ba)關閉(bi)(bi)件從閥(fa)座(zuo)上提起，閥(fa)門打開(kai)；斷電時，電磁力消失，彈簧把(ba)關閉(bi)(bi)件壓在閥(fa)座(zuo)上，閥(fa)門關閉(bi)(bi)。

特點：在真空(kong)、負壓、零壓時能正常工(gong)作，但通徑(jing)一般不超過25mm。

分步直動式(shi)電(dian)磁閥

原理：它是一(yi)種(zhong)直動和先(xian)導(dao)式相結合的原理，當入口(kou)(kou)與(yu)出口(kou)(kou)沒有(you)壓(ya)(ya)差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)直接(jie)把先(xian)導(dao)小閥(fa)(fa)和主閥(fa)(fa)關(guan)閉(bi)件(jian)依次(ci)向上提起，閥(fa)(fa)門(men)(men)打開。當入口(kou)(kou)與(yu)出口(kou)(kou)達到啟動壓(ya)(ya)差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)先(xian)導(dao)小閥(fa)(fa)，主閥(fa)(fa)下(xia)(xia)腔壓(ya)(ya)力(li)上升，上腔壓(ya)(ya)力(li)下(xia)(xia)降，從而利用壓(ya)(ya)差(cha)把主閥(fa)(fa)向上推(tui)開；斷(duan)電(dian)時(shi)，先(xian)導(dao)閥(fa)(fa)利用彈簧力(li)或(huo)介質壓(ya)(ya)力(li)推(tui)動關(guan)閉(bi)件(jian)，向下(xia)(xia)移動，使閥(fa)(fa)門(men)(men)關(guan)閉(bi)。

特(te)點：在零(ling)壓(ya)差或真空、高壓(ya)時亦能可*動作，但(dan)功率較大，要求必須水平安裝(zhuang)。

先導式(shi)電磁閥

原理：通電(dian)時，電(dian)磁力(li)把(ba)先導孔(kong)打開，上(shang)腔(qiang)室壓(ya)力(li)迅(xun)(xun)速下降(jiang)，在關 閉件(jian)周圍(wei)形成上(shang)低下高(gao)的壓(ya)差，流體壓(ya)力(li)推(tui)動關閉件(jian)向(xiang)上(shang)移動，閥門(men)打開；斷(duan)電(dian)時，彈簧(huang)力(li)把(ba)先導孔(kong)關閉，入口(kou)壓(ya)力(li)通過(guo)旁通孔(kong)迅(xun)(xun)速腔(qiang)室在關閥件(jian)周圍(wei)形成下低上(shang)高(gao)的壓(ya)差，流體壓(ya)力(li)推(tui)動關閉件(jian)向(xiang)下移動，關閉閥門(men)。

特點：流體(ti)壓(ya)力(li)范圍上(shang)限較高，可(ke)任意安裝（需定制）但必須滿足流體(ti)壓(ya)差條件。

2、電(dian)磁閥(fa)從(cong)閥(fa)結(jie)(jie)構(gou)(gou)和材(cai)料上的不同與原理上的區別(bie)，分(fen)為六個分(fen)支小類：直動(dong)(dong)膜(mo)片結(jie)(jie)構(gou)(gou)、分(fen)步直動(dong)(dong)膜(mo)片結(jie)(jie)構(gou)(gou)、先(xian)導(dao)膜(mo)片結(jie)(jie)構(gou)(gou)、直動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)、分(fen)步直動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)、先(xian)導(dao)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)按照功能分類：水用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、燃氣(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氣(qi)體(ti)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液體(ti)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)等。