電磁(ci)閥(fa)(fa)(fa)（Electromagnetic valve）是用(yong)(yong)電磁(ci)控制(zhi)的(de)(de)(de)工業(ye)設備，是用(yong)(yong)來控制(zhi)流體的(de)(de)(de)自動(dong)化基礎元件(jian)，屬于執行器，并(bing)不(bu)限(xian)于液(ye)壓、氣動(dong)。用(yong)(yong)在工業(ye)控制(zhi)系(xi)統中調整介質的(de)(de)(de)方向、流量、速度(du)和其他的(de)(de)(de)參數。電磁(ci)閥(fa)(fa)(fa)可以(yi)配合不(bu)同(tong)的(de)(de)(de)電路來實現預期的(de)(de)(de)控制(zhi)，而(er)控制(zhi)的(de)(de)(de)精度(du)和靈活性都能(neng)夠保證。電磁(ci)閥(fa)(fa)(fa)有很多種(zhong)，不(bu)同(tong)的(de)(de)(de)電磁(ci)閥(fa)(fa)(fa)在控制(zhi)系(xi)統的(de)(de)(de)不(bu)同(tong)位置發揮作用(yong)(yong)，最常用(yong)(yong)的(de)(de)(de)是單(dan)向閥(fa)(fa)(fa)、安(an)全閥(fa)(fa)(fa)、方向控制(zhi)閥(fa)(fa)(fa)、速度(du)調節閥(fa)(fa)(fa)等。

電(dian)磁(ci)(ci)閥(fa)(fa)里有(you)密閉(bi)的腔，在(zai)不同位置開(kai)有(you)通孔，每個孔連接不同的油管，腔中(zhong)間是(shi)活塞，兩面是(shi)兩塊電(dian)磁(ci)(ci)鐵(tie)，哪面的磁(ci)(ci)鐵(tie)線圈(quan)通電(dian)閥(fa)(fa)體就(jiu)會被吸引到哪邊，通過(guo)(guo)控制閥(fa)(fa)體的移動(dong)來(lai)開(kai)啟或關閉(bi)不同的排油孔，而進油孔是(shi)常(chang)開(kai)的，液(ye)壓油就(jiu)會進入不同的排油管，然后通過(guo)(guo)油的壓力來(lai)推動(dong)油缸的活塞，活塞又帶(dai)動(dong)活塞桿，活塞桿帶(dai)動(dong)機械(xie)裝置。這樣(yang)通過(guo)(guo)控制電(dian)磁(ci)(ci)鐵(tie)的電(dian)流通斷就(jiu)控制了機械(xie)運動(dong)。

1、電(dian)磁閥(fa)從(cong)原理(li)上(shang)分為三大類：

直動式(shi)電磁閥

原理：通(tong)電(dian)(dian)時(shi)，電(dian)(dian)磁(ci)線圈產生電(dian)(dian)磁(ci)力(li)把關(guan)閉(bi)件從(cong)閥座(zuo)上(shang)提起(qi)，閥門打開(kai)；斷電(dian)(dian)時(shi)，電(dian)(dian)磁(ci)力(li)消失，彈簧把關(guan)閉(bi)件壓在閥座(zuo)上(shang)，閥門關(guan)閉(bi)。

特點：在(zai)真空、負壓、零壓時能正常工作，但通徑一般(ban)不超(chao)過25mm。

分步直動(dong)式電磁(ci)閥(fa)

原理(li)：它是一種直動(dong)(dong)和(he)先導式相結合的原理(li)，當入(ru)(ru)口與出口沒(mei)有壓(ya)差時，通電后，電磁(ci)力直接把先導小(xiao)閥(fa)(fa)(fa)(fa)和(he)主閥(fa)(fa)(fa)(fa)關(guan)(guan)閉(bi)(bi)件(jian)依次向上(shang)(shang)提起(qi)，閥(fa)(fa)(fa)(fa)門打開(kai)。當入(ru)(ru)口與出口達到啟動(dong)(dong)壓(ya)差時，通電后，電磁(ci)力先導小(xiao)閥(fa)(fa)(fa)(fa)，主閥(fa)(fa)(fa)(fa)下腔壓(ya)力上(shang)(shang)升，上(shang)(shang)腔壓(ya)力下降，從而利用壓(ya)差把主閥(fa)(fa)(fa)(fa)向上(shang)(shang)推開(kai)；斷(duan)電時，先導閥(fa)(fa)(fa)(fa)利用彈簧力或(huo)介(jie)質壓(ya)力推動(dong)(dong)關(guan)(guan)閉(bi)(bi)件(jian)，向下移動(dong)(dong)，使閥(fa)(fa)(fa)(fa)門關(guan)(guan)閉(bi)(bi)。

特(te)點(dian)：在(zai)零壓差或真(zhen)空、高壓時亦(yi)能可*動作，但功(gong)率較大(da)，要求必須(xu)水平安裝。

先(xian)導(dao)式電磁閥

原理：通電(dian)時，電(dian)磁(ci)力(li)(li)把先導(dao)孔(kong)(kong)打(da)開，上腔室壓(ya)力(li)(li)迅速(su)下降，在關(guan)(guan) 閉件周圍(wei)形成上低下高的壓(ya)差(cha)，流(liu)體壓(ya)力(li)(li)推動關(guan)(guan)閉件向(xiang)上移動，閥門(men)打(da)開；斷電(dian)時，彈簧力(li)(li)把先導(dao)孔(kong)(kong)關(guan)(guan)閉，入口壓(ya)力(li)(li)通過(guo)旁通孔(kong)(kong)迅速(su)腔室在關(guan)(guan)閥件周圍(wei)形成下低上高的壓(ya)差(cha)，流(liu)體壓(ya)力(li)(li)推動關(guan)(guan)閉件向(xiang)下移動，關(guan)(guan)閉閥門(men)。

特(te)點：流(liu)體壓力范(fan)圍上限(xian)較高，可任意安裝（需定制）但必須滿(man)足流(liu)體壓差條件。

2、電磁閥從閥結(jie)構(gou)(gou)和材(cai)料(liao)上(shang)的不同與原理(li)上(shang)的區別，分(fen)為六(liu)個分(fen)支小類：直(zhi)動膜片(pian)結(jie)構(gou)(gou)、分(fen)步(bu)直(zhi)動膜片(pian)結(jie)構(gou)(gou)、先導(dao)(dao)膜片(pian)結(jie)構(gou)(gou)、直(zhi)動活(huo)塞結(jie)構(gou)(gou)、分(fen)步(bu)直(zhi)動活(huo)塞結(jie)構(gou)(gou)、先導(dao)(dao)活(huo)塞結(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥按照(zhao)功(gong)能分類：水用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、低溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、燃(ran)氣(qi)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、消防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、氨(an)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、氣(qi)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)(ye)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、微(wei)型(xing)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、脈(mo)沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)(ye)壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、油用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、直(zhi)流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥等。