電磁(ci)閥(fa)(fa)（Electromagnetic valve）是用(yong)電磁(ci)控(kong)(kong)制(zhi)(zhi)的(de)(de)(de)(de)工(gong)業(ye)設備(bei)，是用(yong)來控(kong)(kong)制(zhi)(zhi)流體的(de)(de)(de)(de)自動(dong)(dong)化(hua)基礎元件，屬于執行器(qi)，并不(bu)限(xian)于液壓、氣動(dong)(dong)。用(yong)在工(gong)業(ye)控(kong)(kong)制(zhi)(zhi)系(xi)統中調整(zheng)介質的(de)(de)(de)(de)方向(xiang)、流量(liang)、速度和其(qi)他的(de)(de)(de)(de)參(can)數。電磁(ci)閥(fa)(fa)可(ke)以配合不(bu)同的(de)(de)(de)(de)電路來實現預期的(de)(de)(de)(de)控(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)的(de)(de)(de)(de)精度和靈活性(xing)都能夠保證。電磁(ci)閥(fa)(fa)有很多種，不(bu)同的(de)(de)(de)(de)電磁(ci)閥(fa)(fa)在控(kong)(kong)制(zhi)(zhi)系(xi)統的(de)(de)(de)(de)不(bu)同位置發(fa)揮作(zuo)用(yong)，最常用(yong)的(de)(de)(de)(de)是單(dan)向(xiang)閥(fa)(fa)、安(an)全閥(fa)(fa)、方向(xiang)控(kong)(kong)制(zhi)(zhi)閥(fa)(fa)、速度調節閥(fa)(fa)等。

電(dian)磁(ci)閥(fa)里(li)有(you)密閉(bi)的(de)(de)(de)(de)(de)腔(qiang)，在不(bu)同(tong)(tong)位置(zhi)開有(you)通(tong)孔(kong)，每(mei)個(ge)孔(kong)連接不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)油管，腔(qiang)中間是活(huo)塞(sai)(sai)，兩面是兩塊電(dian)磁(ci)鐵，哪面的(de)(de)(de)(de)(de)磁(ci)鐵線圈通(tong)電(dian)閥(fa)體就會被(bei)吸(xi)引(yin)到哪邊，通(tong)過控(kong)制閥(fa)體的(de)(de)(de)(de)(de)移動來開啟或關閉(bi)不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)排油孔(kong)，而進(jin)油孔(kong)是常開的(de)(de)(de)(de)(de)，液壓(ya)油就會進(jin)入不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)排油管，然(ran)后通(tong)過油的(de)(de)(de)(de)(de)壓(ya)力(li)來推動油缸的(de)(de)(de)(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又帶動活(huo)塞(sai)(sai)桿(gan)，活(huo)塞(sai)(sai)桿(gan)帶動機(ji)械裝(zhuang)置(zhi)。這樣通(tong)過控(kong)制電(dian)磁(ci)鐵的(de)(de)(de)(de)(de)電(dian)流通(tong)斷就控(kong)制了(le)機(ji)械運動。

1、電(dian)磁閥從(cong)原理上(shang)分為三大類：

直動(dong)式電磁閥

原(yuan)理(li)：通電(dian)時(shi)，電(dian)磁(ci)線(xian)圈(quan)產生電(dian)磁(ci)力(li)把關(guan)閉件(jian)從閥座(zuo)上提起，閥門打開；斷(duan)電(dian)時(shi)，電(dian)磁(ci)力(li)消(xiao)失，彈(dan)簧(huang)把關(guan)閉件(jian)壓在閥座(zuo)上，閥門關(guan)閉。

特點(dian)：在(zai)真空(kong)、負(fu)壓、零壓時(shi)能正常(chang)工作，但(dan)通(tong)徑一般不超過25mm。

分步直動(dong)式電磁閥

原(yuan)理：它是一(yi)種直(zhi)動(dong)(dong)(dong)和先(xian)導式相結合的(de)原(yuan)理，當(dang)入口與(yu)出口沒有(you)壓(ya)差時，通電(dian)(dian)后，電(dian)(dian)磁力(li)直(zhi)接把先(xian)導小(xiao)閥(fa)和主閥(fa)關閉件依次向上(shang)(shang)提起，閥(fa)門(men)打開(kai)。當(dang)入口與(yu)出口達(da)到啟動(dong)(dong)(dong)壓(ya)差時，通電(dian)(dian)后，電(dian)(dian)磁力(li)先(xian)導小(xiao)閥(fa)，主閥(fa)下(xia)腔壓(ya)力(li)上(shang)(shang)升，上(shang)(shang)腔壓(ya)力(li)下(xia)降，從而利用壓(ya)差把主閥(fa)向上(shang)(shang)推(tui)開(kai)；斷電(dian)(dian)時，先(xian)導閥(fa)利用彈(dan)簧力(li)或介質壓(ya)力(li)推(tui)動(dong)(dong)(dong)關閉件，向下(xia)移(yi)動(dong)(dong)(dong)，使閥(fa)門(men)關閉。

特點：在(zai)零(ling)壓(ya)差或真(zhen)空、高壓(ya)時亦能可*動作，但功率較大，要(yao)求(qiu)必須水平安裝。

先導式電磁閥

原理(li)：通電時，電磁(ci)力把(ba)先(xian)導孔打(da)開(kai)，上(shang)腔室壓(ya)(ya)力迅速(su)下降，在關(guan) 閉(bi)件(jian)周圍形成(cheng)上(shang)低下高(gao)的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力推動(dong)關(guan)閉(bi)件(jian)向(xiang)上(shang)移動(dong)，閥(fa)(fa)門(men)打(da)開(kai)；斷電時，彈簧力把(ba)先(xian)導孔關(guan)閉(bi)，入口壓(ya)(ya)力通過旁通孔迅速(su)腔室在關(guan)閥(fa)(fa)件(jian)周圍形成(cheng)下低上(shang)高(gao)的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力推動(dong)關(guan)閉(bi)件(jian)向(xiang)下移動(dong)，關(guan)閉(bi)閥(fa)(fa)門(men)。

特點(dian)：流(liu)體壓力范圍上限較高，可(ke)任意(yi)安裝（需定制）但必須滿足流(liu)體壓差條件。

2、電磁閥從閥結構和材(cai)料(liao)上(shang)的不同與原理上(shang)的區別(bie)，分(fen)為六個分(fen)支(zhi)小類：直(zhi)動(dong)(dong)膜(mo)片結構、分(fen)步(bu)直(zhi)動(dong)(dong)膜(mo)片結構、先(xian)導膜(mo)片結構、直(zhi)動(dong)(dong)活(huo)(huo)塞結構、分(fen)步(bu)直(zhi)動(dong)(dong)活(huo)(huo)塞結構、先(xian)導活(huo)(huo)塞結構。

3、電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)按(an)照(zhao)功能分類：水用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸(zheng)汽(qi)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、消防電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體(ti)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液(ye)體(ti)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、微型電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液(ye)壓(ya)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、油用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、直流電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆電(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)等。