電磁(ci)閥(fa)(fa)（Electromagnetic valve）是用(yong)電磁(ci)控(kong)制(zhi)(zhi)的(de)(de)工業設備，是用(yong)來控(kong)制(zhi)(zhi)流體的(de)(de)自(zi)動化(hua)基礎(chu)元件，屬(shu)于(yu)執行器，并(bing)不(bu)限于(yu)液壓、氣動。用(yong)在工業控(kong)制(zhi)(zhi)系(xi)統中(zhong)調整介質的(de)(de)方向、流量、速度(du)和其(qi)他的(de)(de)參數。電磁(ci)閥(fa)(fa)可以配合(he)不(bu)同(tong)的(de)(de)電路來實現預(yu)期的(de)(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)(de)精度(du)和靈活性都(dou)能夠保證。電磁(ci)閥(fa)(fa)有很(hen)多種，不(bu)同(tong)的(de)(de)電磁(ci)閥(fa)(fa)在控(kong)制(zhi)(zhi)系(xi)統的(de)(de)不(bu)同(tong)位置發揮作用(yong)，最常用(yong)的(de)(de)是單向閥(fa)(fa)、安全閥(fa)(fa)、方向控(kong)制(zhi)(zhi)閥(fa)(fa)、速度(du)調節閥(fa)(fa)等。

電(dian)(dian)磁(ci)(ci)閥(fa)里有(you)密(mi)閉的(de)(de)腔，在不(bu)(bu)同(tong)位(wei)置(zhi)開有(you)通(tong)(tong)(tong)孔，每(mei)個孔連(lian)接不(bu)(bu)同(tong)的(de)(de)油(you)管，腔中間是(shi)活(huo)塞(sai)，兩面(mian)是(shi)兩塊電(dian)(dian)磁(ci)(ci)鐵，哪面(mian)的(de)(de)磁(ci)(ci)鐵線圈通(tong)(tong)(tong)電(dian)(dian)閥(fa)體(ti)就會被(bei)吸引到哪邊，通(tong)(tong)(tong)過控(kong)制(zhi)(zhi)閥(fa)體(ti)的(de)(de)移動(dong)(dong)來開啟或關閉不(bu)(bu)同(tong)的(de)(de)排油(you)孔，而進(jin)油(you)孔是(shi)常開的(de)(de)，液(ye)壓油(you)就會進(jin)入不(bu)(bu)同(tong)的(de)(de)排油(you)管，然后通(tong)(tong)(tong)過油(you)的(de)(de)壓力來推動(dong)(dong)油(you)缸的(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動(dong)(dong)活(huo)塞(sai)桿，活(huo)塞(sai)桿帶動(dong)(dong)機械裝(zhuang)置(zhi)。這樣通(tong)(tong)(tong)過控(kong)制(zhi)(zhi)電(dian)(dian)磁(ci)(ci)鐵的(de)(de)電(dian)(dian)流通(tong)(tong)(tong)斷(duan)就控(kong)制(zhi)(zhi)了機械運動(dong)(dong)。

1、電磁閥從原(yuan)理上分為三(san)大類：

直動(dong)式電磁(ci)閥

原理：通電(dian)時(shi)，電(dian)磁線圈產生電(dian)磁力(li)把關(guan)閉(bi)件從閥(fa)座上(shang)提起，閥(fa)門打開；斷(duan)電(dian)時(shi)，電(dian)磁力(li)消(xiao)失，彈簧把關(guan)閉(bi)件壓在(zai)閥(fa)座上(shang)，閥(fa)門關(guan)閉(bi)。

特點：在(zai)真空、負(fu)壓、零(ling)壓時能正(zheng)常工作(zuo)，但通徑一(yi)般(ban)不超過(guo)25mm。

分步直(zhi)動式電磁(ci)閥

原(yuan)理：它是一(yi)種直動(dong)(dong)和(he)先(xian)導(dao)式相結合的原(yuan)理，當入口(kou)與(yu)出口(kou)沒有壓差時，通(tong)電(dian)后，電(dian)磁(ci)力(li)直接把(ba)先(xian)導(dao)小閥(fa)和(he)主閥(fa)關(guan)閉(bi)件依次向上(shang)提起，閥(fa)門(men)打開。當入口(kou)與(yu)出口(kou)達到啟動(dong)(dong)壓差時，通(tong)電(dian)后，電(dian)磁(ci)力(li)先(xian)導(dao)小閥(fa)，主閥(fa)下(xia)腔壓力(li)上(shang)升，上(shang)腔壓力(li)下(xia)降(jiang)，從而利用壓差把(ba)主閥(fa)向上(shang)推(tui)開；斷電(dian)時，先(xian)導(dao)閥(fa)利用彈簧力(li)或介質壓力(li)推(tui)動(dong)(dong)關(guan)閉(bi)件，向下(xia)移動(dong)(dong)，使閥(fa)門(men)關(guan)閉(bi)。

特點：在零壓差或(huo)真空(kong)、高(gao)壓時亦能可*動作，但功(gong)率較大，要求必須水(shui)平安(an)裝。

先導(dao)式電磁閥

原理：通(tong)(tong)電(dian)時(shi)，電(dian)磁力把(ba)先導孔打開，上腔(qiang)室壓(ya)力迅速下降，在關(guan) 閉(bi)件(jian)(jian)周圍形成上低(di)下高(gao)的(de)壓(ya)差(cha)，流(liu)體(ti)壓(ya)力推(tui)動(dong)(dong)關(guan)閉(bi)件(jian)(jian)向上移動(dong)(dong)，閥門(men)打開；斷電(dian)時(shi)，彈(dan)簧力把(ba)先導孔關(guan)閉(bi)，入口(kou)壓(ya)力通(tong)(tong)過旁通(tong)(tong)孔迅速腔(qiang)室在關(guan)閥件(jian)(jian)周圍形成下低(di)上高(gao)的(de)壓(ya)差(cha)，流(liu)體(ti)壓(ya)力推(tui)動(dong)(dong)關(guan)閉(bi)件(jian)(jian)向下移動(dong)(dong)，關(guan)閉(bi)閥門(men)。

特點：流體壓(ya)力(li)范圍上(shang)限較高，可(ke)任意安裝（需定制）但(dan)必(bi)須(xu)滿(man)足流體壓(ya)差條件。

2、電磁閥從閥結(jie)構(gou)和材料上的不同(tong)與(yu)原理上的區別，分為六個分支小類：直(zhi)(zhi)動(dong)(dong)膜(mo)(mo)片結(jie)構(gou)、分步直(zhi)(zhi)動(dong)(dong)膜(mo)(mo)片結(jie)構(gou)、先(xian)(xian)導膜(mo)(mo)片結(jie)構(gou)、直(zhi)(zhi)動(dong)(dong)活(huo)塞結(jie)構(gou)、分步直(zhi)(zhi)動(dong)(dong)活(huo)塞結(jie)構(gou)、先(xian)(xian)導活(huo)塞結(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按照(zhao)功能分(fen)類：水用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸(zheng)汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖(chong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常(chang)開(kai)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆(bao)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等。