電(dian)(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是用電(dian)(dian)磁(ci)控(kong)制(zhi)的(de)(de)(de)(de)工業設(she)備(bei)，是用來控(kong)制(zhi)流(liu)(liu)體的(de)(de)(de)(de)自動化基礎(chu)元件，屬于執行器，并不限(xian)于液(ye)壓、氣動。用在工業控(kong)制(zhi)系(xi)統(tong)(tong)中(zhong)調整(zheng)介質的(de)(de)(de)(de)方(fang)向(xiang)、流(liu)(liu)量(liang)、速(su)度(du)和其他的(de)(de)(de)(de)參數。電(dian)(dian)磁(ci)閥(fa)(fa)可以配合不同(tong)的(de)(de)(de)(de)電(dian)(dian)路來實(shi)現預期的(de)(de)(de)(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)(de)(de)(de)精度(du)和靈(ling)活性都能夠保(bao)證(zheng)。電(dian)(dian)磁(ci)閥(fa)(fa)有很多種，不同(tong)的(de)(de)(de)(de)電(dian)(dian)磁(ci)閥(fa)(fa)在控(kong)制(zhi)系(xi)統(tong)(tong)的(de)(de)(de)(de)不同(tong)位置發揮作用，最常(chang)用的(de)(de)(de)(de)是單向(xiang)閥(fa)(fa)、安(an)全閥(fa)(fa)、方(fang)向(xiang)控(kong)制(zhi)閥(fa)(fa)、速(su)度(du)調節閥(fa)(fa)等。

電(dian)磁閥里(li)有密閉的(de)(de)(de)腔，在(zai)不(bu)(bu)同(tong)位置開(kai)有通(tong)(tong)(tong)孔(kong)，每個孔(kong)連接不(bu)(bu)同(tong)的(de)(de)(de)油(you)管，腔中間是活(huo)(huo)塞(sai)，兩(liang)面是兩(liang)塊電(dian)磁鐵，哪面的(de)(de)(de)磁鐵線圈通(tong)(tong)(tong)電(dian)閥體就(jiu)會被(bei)吸引(yin)到哪邊，通(tong)(tong)(tong)過(guo)控制(zhi)閥體的(de)(de)(de)移動來開(kai)啟或關(guan)閉不(bu)(bu)同(tong)的(de)(de)(de)排油(you)孔(kong)，而進(jin)油(you)孔(kong)是常開(kai)的(de)(de)(de)，液壓油(you)就(jiu)會進(jin)入不(bu)(bu)同(tong)的(de)(de)(de)排油(you)管，然后通(tong)(tong)(tong)過(guo)油(you)的(de)(de)(de)壓力來推動油(you)缸的(de)(de)(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又帶動活(huo)(huo)塞(sai)桿(gan)，活(huo)(huo)塞(sai)桿(gan)帶動機(ji)(ji)械(xie)裝(zhuang)置。這樣通(tong)(tong)(tong)過(guo)控制(zhi)電(dian)磁鐵的(de)(de)(de)電(dian)流(liu)通(tong)(tong)(tong)斷就(jiu)控制(zhi)了機(ji)(ji)械(xie)運動。

1、電磁閥(fa)從原理(li)上分(fen)為三大類：

直(zhi)動式電磁閥

原理：通電(dian)(dian)時，電(dian)(dian)磁(ci)(ci)線圈產生電(dian)(dian)磁(ci)(ci)力把關閉(bi)(bi)件(jian)從閥座上提起(qi)，閥門打開；斷電(dian)(dian)時，電(dian)(dian)磁(ci)(ci)力消(xiao)失，彈簧(huang)把關閉(bi)(bi)件(jian)壓在閥座上，閥門關閉(bi)(bi)。

特點：在真空(kong)、負壓、零壓時能正常(chang)工作(zuo)，但(dan)通徑一(yi)般不(bu)超過(guo)25mm。

分步直動式電(dian)磁(ci)閥

原(yuan)理：它(ta)是一種直動(dong)和先導(dao)式相結合的原(yuan)理，當入(ru)口(kou)(kou)與出(chu)口(kou)(kou)沒(mei)有(you)壓差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)直接把先導(dao)小(xiao)(xiao)閥(fa)和主閥(fa)關(guan)閉(bi)件(jian)(jian)依次(ci)向上(shang)(shang)(shang)提起(qi)，閥(fa)門打開(kai)(kai)。當入(ru)口(kou)(kou)與出(chu)口(kou)(kou)達到啟動(dong)壓差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)先導(dao)小(xiao)(xiao)閥(fa)，主閥(fa)下腔壓力(li)上(shang)(shang)(shang)升，上(shang)(shang)(shang)腔壓力(li)下降，從(cong)而利(li)用(yong)壓差(cha)把主閥(fa)向上(shang)(shang)(shang)推開(kai)(kai)；斷電(dian)時(shi)，先導(dao)閥(fa)利(li)用(yong)彈簧力(li)或介質壓力(li)推動(dong)關(guan)閉(bi)件(jian)(jian)，向下移(yi)動(dong)，使閥(fa)門關(guan)閉(bi)。

特點：在零壓(ya)差或真空、高壓(ya)時亦能可*動作，但功(gong)率較大，要求必(bi)須水平(ping)安裝。

先導(dao)式電磁閥

原理：通電(dian)時(shi)，電(dian)磁力把先(xian)(xian)導(dao)孔(kong)(kong)打開，上(shang)(shang)腔(qiang)室壓(ya)(ya)力迅速下(xia)(xia)降，在(zai)關 閉(bi)(bi)(bi)件(jian)周(zhou)圍形成上(shang)(shang)低下(xia)(xia)高的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力推動關閉(bi)(bi)(bi)件(jian)向(xiang)上(shang)(shang)移(yi)動，閥(fa)門打開；斷電(dian)時(shi)，彈簧力把先(xian)(xian)導(dao)孔(kong)(kong)關閉(bi)(bi)(bi)，入口壓(ya)(ya)力通過旁通孔(kong)(kong)迅速腔(qiang)室在(zai)關閥(fa)件(jian)周(zhou)圍形成下(xia)(xia)低上(shang)(shang)高的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力推動關閉(bi)(bi)(bi)件(jian)向(xiang)下(xia)(xia)移(yi)動，關閉(bi)(bi)(bi)閥(fa)門。

特點：流體壓(ya)力范圍(wei)上限較高，可任意安裝（需(xu)定制）但必須滿足流體壓(ya)差條件。

2、電磁(ci)閥從閥結(jie)構(gou)和材(cai)料上的不(bu)同(tong)與原理上的區別(bie)，分(fen)為六個分(fen)支小類：直動(dong)膜(mo)(mo)片結(jie)構(gou)、分(fen)步直動(dong)膜(mo)(mo)片結(jie)構(gou)、先導膜(mo)(mo)片結(jie)構(gou)、直動(dong)活塞(sai)結(jie)構(gou)、分(fen)步直動(dong)活塞(sai)結(jie)構(gou)、先導活塞(sai)結(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥按照功(gong)能(neng)分類(lei)：水(shui)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、蒸(zheng)汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、制(zhi)冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、低(di)溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、燃(ran)氣(qi)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、消(xiao)防(fang)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、氨用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、氣(qi)體(ti)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)體(ti)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、微型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、脈沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)壓(ya)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥 常開(kai)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、油用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、直流(liu)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、高(gao)壓(ya)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、防(fang)爆(bao)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥等。