電磁(ci)(ci)(ci)閥(fa)（Electromagnetic valve）是(shi)(shi)用電磁(ci)(ci)(ci)控(kong)制(zhi)(zhi)的(de)(de)(de)(de)工業(ye)設備，是(shi)(shi)用來控(kong)制(zhi)(zhi)流體的(de)(de)(de)(de)自動(dong)化(hua)基礎元件，屬于(yu)執行(xing)器，并(bing)不(bu)限于(yu)液壓、氣動(dong)。用在(zai)工業(ye)控(kong)制(zhi)(zhi)系統(tong)中調整介質的(de)(de)(de)(de)方(fang)向(xiang)(xiang)、流量、速(su)度(du)和其他(ta)的(de)(de)(de)(de)參數。電磁(ci)(ci)(ci)閥(fa)可以配合不(bu)同(tong)的(de)(de)(de)(de)電路(lu)來實現(xian)預期的(de)(de)(de)(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)(de)(de)(de)精度(du)和靈活性都能夠保證。電磁(ci)(ci)(ci)閥(fa)有很多種，不(bu)同(tong)的(de)(de)(de)(de)電磁(ci)(ci)(ci)閥(fa)在(zai)控(kong)制(zhi)(zhi)系統(tong)的(de)(de)(de)(de)不(bu)同(tong)位置發揮作用，最常(chang)用的(de)(de)(de)(de)是(shi)(shi)單向(xiang)(xiang)閥(fa)、安全(quan)閥(fa)、方(fang)向(xiang)(xiang)控(kong)制(zhi)(zhi)閥(fa)、速(su)度(du)調節閥(fa)等。

電(dian)(dian)磁(ci)閥(fa)里(li)有密閉的(de)(de)(de)腔(qiang)，在不(bu)同位(wei)置開(kai)有通(tong)(tong)孔(kong)，每個(ge)孔(kong)連(lian)接不(bu)同的(de)(de)(de)油管(guan)，腔(qiang)中(zhong)間(jian)是活(huo)塞(sai)，兩面(mian)(mian)是兩塊電(dian)(dian)磁(ci)鐵(tie)，哪面(mian)(mian)的(de)(de)(de)磁(ci)鐵(tie)線圈通(tong)(tong)電(dian)(dian)閥(fa)體就(jiu)會(hui)被(bei)吸引到哪邊，通(tong)(tong)過(guo)控制閥(fa)體的(de)(de)(de)移動(dong)來開(kai)啟或關閉不(bu)同的(de)(de)(de)排油孔(kong)，而進油孔(kong)是常開(kai)的(de)(de)(de)，液壓油就(jiu)會(hui)進入不(bu)同的(de)(de)(de)排油管(guan)，然后通(tong)(tong)過(guo)油的(de)(de)(de)壓力來推(tui)動(dong)油缸的(de)(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又(you)帶(dai)動(dong)活(huo)塞(sai)桿(gan)，活(huo)塞(sai)桿(gan)帶(dai)動(dong)機械(xie)裝置。這樣通(tong)(tong)過(guo)控制電(dian)(dian)磁(ci)鐵(tie)的(de)(de)(de)電(dian)(dian)流通(tong)(tong)斷(duan)就(jiu)控制了機械(xie)運動(dong)。

1、電(dian)磁(ci)閥從原理(li)上(shang)分(fen)為三大類：

直(zhi)動式電磁(ci)閥

原理：通(tong)電(dian)時(shi)，電(dian)磁(ci)線(xian)圈(quan)產生電(dian)磁(ci)力把(ba)關閉(bi)件從閥(fa)(fa)(fa)座上提起(qi)，閥(fa)(fa)(fa)門打開；斷電(dian)時(shi)，電(dian)磁(ci)力消失，彈簧把(ba)關閉(bi)件壓在(zai)閥(fa)(fa)(fa)座上，閥(fa)(fa)(fa)門關閉(bi)。

特(te)點：在真空(kong)、負壓、零壓時能正常工作，但通徑一(yi)般(ban)不超過25mm。

分步直動(dong)式電磁閥

原理：它(ta)是一種(zhong)直(zhi)動(dong)和(he)先導(dao)式相結合的原理，當(dang)入(ru)口與出(chu)口沒有壓差時，通電后，電磁力(li)(li)直(zhi)接(jie)把(ba)先導(dao)小閥(fa)和(he)主閥(fa)關(guan)(guan)閉件依次向(xiang)上提(ti)起，閥(fa)門打開。當(dang)入(ru)口與出(chu)口達到啟(qi)動(dong)壓差時，通電后，電磁力(li)(li)先導(dao)小閥(fa)，主閥(fa)下(xia)腔壓力(li)(li)上升，上腔壓力(li)(li)下(xia)降，從而利用壓差把(ba)主閥(fa)向(xiang)上推開；斷電時，先導(dao)閥(fa)利用彈簧(huang)力(li)(li)或介(jie)質壓力(li)(li)推動(dong)關(guan)(guan)閉件，向(xiang)下(xia)移動(dong)，使閥(fa)門關(guan)(guan)閉。

特點：在(zai)零壓差或真(zhen)空、高壓時亦能可*動(dong)作，但功率較大，要求必須水平安裝。

先導式電磁閥(fa)

原理：通(tong)電(dian)時，電(dian)磁(ci)力(li)把先導孔(kong)(kong)打(da)開，上(shang)腔室壓(ya)(ya)力(li)迅(xun)速下(xia)降，在(zai)關 閉(bi)件(jian)周圍形成上(shang)低下(xia)高(gao)的壓(ya)(ya)差(cha)，流體壓(ya)(ya)力(li)推動關閉(bi)件(jian)向上(shang)移動，閥(fa)(fa)門打(da)開；斷電(dian)時，彈簧力(li)把先導孔(kong)(kong)關閉(bi)，入口壓(ya)(ya)力(li)通(tong)過旁通(tong)孔(kong)(kong)迅(xun)速腔室在(zai)關閥(fa)(fa)件(jian)周圍形成下(xia)低上(shang)高(gao)的壓(ya)(ya)差(cha)，流體壓(ya)(ya)力(li)推動關閉(bi)件(jian)向下(xia)移動，關閉(bi)閥(fa)(fa)門。

特點：流(liu)體壓(ya)力(li)范圍(wei)上(shang)限(xian)較高，可任(ren)意安(an)裝（需定制）但必(bi)須滿(man)足流(liu)體壓(ya)差條件。

2、電磁閥(fa)從閥(fa)結構和材料上的(de)(de)不(bu)同與(yu)原理上的(de)(de)區(qu)別，分(fen)為六(liu)個分(fen)支小類：直(zhi)動膜(mo)片結構、分(fen)步直(zhi)動膜(mo)片結構、先導(dao)膜(mo)片結構、直(zhi)動活(huo)塞結構、分(fen)步直(zhi)動活(huo)塞結構、先導(dao)活(huo)塞結構。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)按照功能分類：水用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、燃(ran)氣電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、消防(fang)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體(ti)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液體(ti)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖(chong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、防(fang)爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)等(deng)。