電磁(ci)(ci)閥(fa)（Electromagnetic valve）是用(yong)(yong)電磁(ci)(ci)控制(zhi)(zhi)(zhi)的(de)(de)(de)(de)工業設備(bei)，是用(yong)(yong)來(lai)控制(zhi)(zhi)(zhi)流體的(de)(de)(de)(de)自動(dong)化(hua)基(ji)礎元件，屬于執行器(qi)，并不(bu)限(xian)于液壓、氣動(dong)。用(yong)(yong)在工業控制(zhi)(zhi)(zhi)系(xi)統中(zhong)調整介質的(de)(de)(de)(de)方向(xiang)、流量(liang)、速(su)度(du)(du)和(he)其(qi)他的(de)(de)(de)(de)參數。電磁(ci)(ci)閥(fa)可以配合(he)不(bu)同(tong)(tong)的(de)(de)(de)(de)電路來(lai)實現預期的(de)(de)(de)(de)控制(zhi)(zhi)(zhi)，而(er)控制(zhi)(zhi)(zhi)的(de)(de)(de)(de)精度(du)(du)和(he)靈活性都(dou)能夠保證。電磁(ci)(ci)閥(fa)有很多種，不(bu)同(tong)(tong)的(de)(de)(de)(de)電磁(ci)(ci)閥(fa)在控制(zhi)(zhi)(zhi)系(xi)統的(de)(de)(de)(de)不(bu)同(tong)(tong)位置發揮作用(yong)(yong)，最常用(yong)(yong)的(de)(de)(de)(de)是單向(xiang)閥(fa)、安全閥(fa)、方向(xiang)控制(zhi)(zhi)(zhi)閥(fa)、速(su)度(du)(du)調節(jie)閥(fa)等。

電(dian)磁閥(fa)里有密閉的(de)(de)(de)腔(qiang)，在(zai)不(bu)(bu)同位置(zhi)(zhi)開有通(tong)(tong)(tong)(tong)孔，每個孔連(lian)接不(bu)(bu)同的(de)(de)(de)油(you)(you)管(guan)，腔(qiang)中間(jian)是(shi)活(huo)塞(sai)(sai)，兩面(mian)是(shi)兩塊電(dian)磁鐵，哪面(mian)的(de)(de)(de)磁鐵線圈通(tong)(tong)(tong)(tong)電(dian)閥(fa)體就(jiu)(jiu)會(hui)被吸引到哪邊，通(tong)(tong)(tong)(tong)過(guo)控(kong)(kong)制(zhi)閥(fa)體的(de)(de)(de)移動(dong)(dong)(dong)來開啟或關閉不(bu)(bu)同的(de)(de)(de)排油(you)(you)孔，而(er)進(jin)油(you)(you)孔是(shi)常開的(de)(de)(de)，液壓油(you)(you)就(jiu)(jiu)會(hui)進(jin)入不(bu)(bu)同的(de)(de)(de)排油(you)(you)管(guan)，然后(hou)通(tong)(tong)(tong)(tong)過(guo)油(you)(you)的(de)(de)(de)壓力(li)來推(tui)動(dong)(dong)(dong)油(you)(you)缸的(de)(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又帶動(dong)(dong)(dong)活(huo)塞(sai)(sai)桿，活(huo)塞(sai)(sai)桿帶動(dong)(dong)(dong)機械(xie)裝置(zhi)(zhi)。這樣通(tong)(tong)(tong)(tong)過(guo)控(kong)(kong)制(zhi)電(dian)磁鐵的(de)(de)(de)電(dian)流通(tong)(tong)(tong)(tong)斷就(jiu)(jiu)控(kong)(kong)制(zhi)了機械(xie)運動(dong)(dong)(dong)。

1、電(dian)磁閥從原理上分(fen)為三大(da)類(lei)：

直動式電磁閥(fa)

原理：通電(dian)時，電(dian)磁(ci)線圈產(chan)生電(dian)磁(ci)力把關閉件從閥(fa)(fa)座(zuo)上提起，閥(fa)(fa)門(men)打(da)開；斷電(dian)時，電(dian)磁(ci)力消失，彈簧把關閉件壓(ya)在閥(fa)(fa)座(zuo)上，閥(fa)(fa)門(men)關閉。

特(te)點：在真(zhen)空、負壓、零壓時能正常工作，但(dan)通(tong)徑一般不(bu)超過(guo)25mm。

分步直動式電磁閥(fa)

原(yuan)理(li)(li)：它是一種直動(dong)(dong)和先導(dao)式相(xiang)結合的原(yuan)理(li)(li)，當(dang)入(ru)(ru)口與(yu)出(chu)口沒有壓差(cha)(cha)時，通電(dian)后，電(dian)磁力(li)直接把先導(dao)小閥(fa)(fa)和主(zhu)閥(fa)(fa)關閉(bi)件(jian)依次向上(shang)提(ti)起，閥(fa)(fa)門打開(kai)。當(dang)入(ru)(ru)口與(yu)出(chu)口達(da)到(dao)啟動(dong)(dong)壓差(cha)(cha)時，通電(dian)后，電(dian)磁力(li)先導(dao)小閥(fa)(fa)，主(zhu)閥(fa)(fa)下腔壓力(li)上(shang)升，上(shang)腔壓力(li)下降，從而(er)利(li)用壓差(cha)(cha)把主(zhu)閥(fa)(fa)向上(shang)推(tui)開(kai)；斷電(dian)時，先導(dao)閥(fa)(fa)利(li)用彈簧力(li)或介質壓力(li)推(tui)動(dong)(dong)關閉(bi)件(jian)，向下移(yi)動(dong)(dong)，使閥(fa)(fa)門關閉(bi)。

特(te)點(dian)：在零壓差或真(zhen)空(kong)、高壓時(shi)亦能可*動作，但功率較大(da)，要求必(bi)須(xu)水平安裝。

先(xian)導式電磁閥

原(yuan)理：通電(dian)(dian)時(shi)，電(dian)(dian)磁力把先(xian)導孔打(da)開，上(shang)腔室壓(ya)(ya)力迅(xun)速(su)下降，在關 閉(bi)件周(zhou)圍形成上(shang)低(di)下高(gao)的壓(ya)(ya)差，流體(ti)壓(ya)(ya)力推動(dong)關閉(bi)件向上(shang)移(yi)動(dong)，閥門打(da)開；斷電(dian)(dian)時(shi)，彈簧力把先(xian)導孔關閉(bi)，入口壓(ya)(ya)力通過(guo)旁(pang)通孔迅(xun)速(su)腔室在關閥件周(zhou)圍形成下低(di)上(shang)高(gao)的壓(ya)(ya)差，流體(ti)壓(ya)(ya)力推動(dong)關閉(bi)件向下移(yi)動(dong)，關閉(bi)閥門。

特點：流(liu)體(ti)壓(ya)力范圍上限較(jiao)高(gao)，可任意安裝（需定制）但必須滿足流(liu)體(ti)壓(ya)差條件。

2、電磁閥從閥結構(gou)(gou)(gou)和材料上(shang)的不同與(yu)原理上(shang)的區別，分為(wei)六個(ge)分支小類：直動膜片(pian)結構(gou)(gou)(gou)、分步(bu)直動膜片(pian)結構(gou)(gou)(gou)、先(xian)導膜片(pian)結構(gou)(gou)(gou)、直動活(huo)塞結構(gou)(gou)(gou)、分步(bu)直動活(huo)塞結構(gou)(gou)(gou)、先(xian)導活(huo)塞結構(gou)(gou)(gou)。

3、電(dian)(dian)(dian)磁(ci)(ci)閥(fa)按(an)照功(gong)能分類：水用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、蒸汽電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、制冷電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、低(di)溫(wen)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、燃氣(qi)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、消防電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氨用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氣(qi)體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、微型(xing)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、脈沖電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa) 常(chang)開(kai)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、油用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、直(zhi)流電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、高(gao)壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、防爆電(dian)(dian)(dian)磁(ci)(ci)閥(fa)等。