電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)（Electromagnetic valve）是用(yong)(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)控(kong)(kong)制(zhi)的(de)(de)(de)工(gong)業設備，是用(yong)(yong)(yong)來(lai)控(kong)(kong)制(zhi)流體的(de)(de)(de)自動(dong)化基礎元件，屬(shu)于執行器，并不(bu)限于液壓、氣動(dong)。用(yong)(yong)(yong)在(zai)工(gong)業控(kong)(kong)制(zhi)系統中(zhong)調整介質的(de)(de)(de)方向、流量、速度和其(qi)他的(de)(de)(de)參數。電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)可以配合不(bu)同的(de)(de)(de)電(dian)(dian)(dian)路來(lai)實現(xian)預期的(de)(de)(de)控(kong)(kong)制(zhi)，而控(kong)(kong)制(zhi)的(de)(de)(de)精(jing)度和靈活性(xing)都能夠保證。電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)有很多(duo)種，不(bu)同的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)在(zai)控(kong)(kong)制(zhi)系統的(de)(de)(de)不(bu)同位置發(fa)揮(hui)作用(yong)(yong)(yong)，最常用(yong)(yong)(yong)的(de)(de)(de)是單向閥(fa)(fa)(fa)(fa)(fa)、安全閥(fa)(fa)(fa)(fa)(fa)、方向控(kong)(kong)制(zhi)閥(fa)(fa)(fa)(fa)(fa)、速度調節閥(fa)(fa)(fa)(fa)(fa)等(deng)。

電磁(ci)閥(fa)里(li)有(you)密(mi)閉(bi)的(de)腔，在不(bu)同(tong)位(wei)置開有(you)通(tong)孔，每個(ge)孔連接不(bu)同(tong)的(de)油管(guan)，腔中間是(shi)活(huo)塞，兩面是(shi)兩塊電磁(ci)鐵，哪面的(de)磁(ci)鐵線圈通(tong)電閥(fa)體(ti)就(jiu)會(hui)被吸(xi)引到哪邊，通(tong)過(guo)控(kong)制閥(fa)體(ti)的(de)移(yi)動(dong)來開啟或關閉(bi)不(bu)同(tong)的(de)排油孔，而(er)進油孔是(shi)常開的(de)，液壓(ya)油就(jiu)會(hui)進入(ru)不(bu)同(tong)的(de)排油管(guan)，然后通(tong)過(guo)油的(de)壓(ya)力來推動(dong)油缸的(de)活(huo)塞，活(huo)塞又帶(dai)(dai)動(dong)活(huo)塞桿(gan)，活(huo)塞桿(gan)帶(dai)(dai)動(dong)機械(xie)裝置。這樣通(tong)過(guo)控(kong)制電磁(ci)鐵的(de)電流通(tong)斷就(jiu)控(kong)制了機械(xie)運(yun)動(dong)。

1、電磁(ci)閥從原理上分為三大類：

直動式電(dian)磁閥

原理：通(tong)電時(shi)(shi)，電磁線圈產生(sheng)電磁力把關閉(bi)件(jian)從閥座上(shang)提起，閥門(men)打開(kai)；斷(duan)電時(shi)(shi)，電磁力消失(shi)，彈簧把關閉(bi)件(jian)壓在閥座上(shang)，閥門(men)關閉(bi)。

特點：在真空、負壓(ya)、零壓(ya)時能正常(chang)工(gong)作，但(dan)通徑一般不(bu)超過25mm。

分步直動式電磁(ci)閥

原理：它是一種(zhong)直動和(he)先(xian)導(dao)式相結(jie)合的原理，當入口與出口沒有壓差時(shi)，通電(dian)后(hou)，電(dian)磁(ci)力(li)直接把(ba)(ba)先(xian)導(dao)小閥(fa)和(he)主(zhu)閥(fa)關(guan)閉(bi)件依次向上提起，閥(fa)門(men)打(da)開。當入口與出口達(da)到啟動壓差時(shi)，通電(dian)后(hou)，電(dian)磁(ci)力(li)先(xian)導(dao)小閥(fa)，主(zhu)閥(fa)下腔(qiang)壓力(li)上升，上腔(qiang)壓力(li)下降(jiang)，從而利用壓差把(ba)(ba)主(zhu)閥(fa)向上推(tui)開；斷電(dian)時(shi)，先(xian)導(dao)閥(fa)利用彈簧力(li)或介(jie)質壓力(li)推(tui)動關(guan)閉(bi)件，向下移(yi)動，使閥(fa)門(men)關(guan)閉(bi)。

特點：在零壓(ya)差或(huo)真空、高壓(ya)時亦能可*動作，但功率較大，要求必須水平(ping)安(an)裝。

先導式電(dian)磁閥

原理(li)：通電時，電磁力(li)(li)(li)把先導(dao)孔(kong)打(da)開，上(shang)腔室壓(ya)(ya)(ya)力(li)(li)(li)迅速(su)下(xia)降，在(zai)關(guan) 閉件周圍形(xing)成上(shang)低下(xia)高(gao)的壓(ya)(ya)(ya)差，流(liu)體(ti)壓(ya)(ya)(ya)力(li)(li)(li)推(tui)動(dong)關(guan)閉件向上(shang)移(yi)動(dong)，閥(fa)(fa)門打(da)開；斷電時，彈簧(huang)力(li)(li)(li)把先導(dao)孔(kong)關(guan)閉，入口壓(ya)(ya)(ya)力(li)(li)(li)通過旁通孔(kong)迅速(su)腔室在(zai)關(guan)閥(fa)(fa)件周圍形(xing)成下(xia)低上(shang)高(gao)的壓(ya)(ya)(ya)差，流(liu)體(ti)壓(ya)(ya)(ya)力(li)(li)(li)推(tui)動(dong)關(guan)閉件向下(xia)移(yi)動(dong)，關(guan)閉閥(fa)(fa)門。

特點：流體(ti)壓力范圍(wei)上(shang)限(xian)較高，可任意(yi)安(an)裝（需定(ding)制）但必(bi)須滿足流體(ti)壓差條件。

2、電磁閥從閥結(jie)(jie)(jie)構和材料上的不同與原(yuan)理上的區(qu)別(bie)，分(fen)(fen)(fen)為六(liu)個(ge)分(fen)(fen)(fen)支(zhi)小類：直(zhi)動膜片(pian)結(jie)(jie)(jie)構、分(fen)(fen)(fen)步直(zhi)動膜片(pian)結(jie)(jie)(jie)構、先導膜片(pian)結(jie)(jie)(jie)構、直(zhi)動活(huo)塞結(jie)(jie)(jie)構、分(fen)(fen)(fen)步直(zhi)動活(huo)塞結(jie)(jie)(jie)構、先導活(huo)塞結(jie)(jie)(jie)構。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)按照(zhao)功能分類：水用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、蒸(zheng)汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氣體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)等。