電磁(ci)閥(fa)(fa)(fa)（Electromagnetic valve）是(shi)用(yong)(yong)電磁(ci)控(kong)制(zhi)的(de)(de)工(gong)業設備，是(shi)用(yong)(yong)來控(kong)制(zhi)流體的(de)(de)自動(dong)化基礎元件，屬于執行(xing)器，并不限于液壓、氣動(dong)。用(yong)(yong)在工(gong)業控(kong)制(zhi)系統中調(diao)(diao)整介質的(de)(de)方向(xiang)(xiang)、流量、速度(du)和其他的(de)(de)參數。電磁(ci)閥(fa)(fa)(fa)可以配合(he)不同的(de)(de)電路來實現預期(qi)的(de)(de)控(kong)制(zhi)，而(er)控(kong)制(zhi)的(de)(de)精度(du)和靈活(huo)性(xing)都能夠保證。電磁(ci)閥(fa)(fa)(fa)有很多種(zhong)，不同的(de)(de)電磁(ci)閥(fa)(fa)(fa)在控(kong)制(zhi)系統的(de)(de)不同位置發(fa)揮作(zuo)用(yong)(yong)，最常用(yong)(yong)的(de)(de)是(shi)單(dan)向(xiang)(xiang)閥(fa)(fa)(fa)、安全閥(fa)(fa)(fa)、方向(xiang)(xiang)控(kong)制(zhi)閥(fa)(fa)(fa)、速度(du)調(diao)(diao)節(jie)閥(fa)(fa)(fa)等。

電(dian)(dian)磁閥(fa)(fa)里有(you)密閉的(de)(de)(de)腔(qiang)(qiang)，在不(bu)(bu)同(tong)(tong)位置(zhi)開有(you)通(tong)孔(kong)(kong)，每(mei)個孔(kong)(kong)連接不(bu)(bu)同(tong)(tong)的(de)(de)(de)油(you)管(guan)，腔(qiang)(qiang)中間是(shi)活塞(sai)，兩面是(shi)兩塊電(dian)(dian)磁鐵，哪面的(de)(de)(de)磁鐵線圈通(tong)電(dian)(dian)閥(fa)(fa)體就(jiu)會被吸引到(dao)哪邊，通(tong)過控(kong)制閥(fa)(fa)體的(de)(de)(de)移動(dong)來(lai)開啟(qi)或關閉不(bu)(bu)同(tong)(tong)的(de)(de)(de)排油(you)孔(kong)(kong)，而進油(you)孔(kong)(kong)是(shi)常開的(de)(de)(de)，液壓油(you)就(jiu)會進入不(bu)(bu)同(tong)(tong)的(de)(de)(de)排油(you)管(guan)，然后通(tong)過油(you)的(de)(de)(de)壓力來(lai)推動(dong)油(you)缸的(de)(de)(de)活塞(sai)，活塞(sai)又帶動(dong)活塞(sai)桿(gan)(gan)，活塞(sai)桿(gan)(gan)帶動(dong)機械(xie)裝(zhuang)置(zhi)。這樣通(tong)過控(kong)制電(dian)(dian)磁鐵的(de)(de)(de)電(dian)(dian)流(liu)通(tong)斷就(jiu)控(kong)制了機械(xie)運動(dong)。

1、電磁閥(fa)從原理上(shang)分(fen)為(wei)三大(da)類：

直動式電磁閥

原(yuan)理：通電(dian)時(shi)，電(dian)磁(ci)線圈產生電(dian)磁(ci)力把關閉件(jian)(jian)從閥座(zuo)(zuo)上提起(qi)，閥門打開(kai)；斷電(dian)時(shi)，電(dian)磁(ci)力消失(shi)，彈簧把關閉件(jian)(jian)壓在閥座(zuo)(zuo)上，閥門關閉。

特點：在真空、負壓、零壓時能正常工作，但(dan)通徑一般(ban)不超過25mm。

分步直動式電磁閥

原(yuan)理(li)：它是一種直(zhi)動和先導(dao)式(shi)相結合的原(yuan)理(li)，當入口(kou)與出口(kou)沒(mei)有壓(ya)(ya)(ya)差(cha)時，通(tong)電(dian)后，電(dian)磁力(li)直(zhi)接把先導(dao)小閥(fa)和主閥(fa)關(guan)閉(bi)件依次(ci)向(xiang)上提(ti)起(qi)，閥(fa)門打(da)開。當入口(kou)與出口(kou)達(da)到啟(qi)動壓(ya)(ya)(ya)差(cha)時，通(tong)電(dian)后，電(dian)磁力(li)先導(dao)小閥(fa)，主閥(fa)下腔壓(ya)(ya)(ya)力(li)上升，上腔壓(ya)(ya)(ya)力(li)下降，從而利(li)用(yong)壓(ya)(ya)(ya)差(cha)把主閥(fa)向(xiang)上推開；斷電(dian)時，先導(dao)閥(fa)利(li)用(yong)彈簧力(li)或介質壓(ya)(ya)(ya)力(li)推動關(guan)閉(bi)件，向(xiang)下移動，使閥(fa)門關(guan)閉(bi)。

特點：在零壓差(cha)或真空、高壓時亦(yi)能可*動作，但(dan)功率較(jiao)大，要求(qiu)必須(xu)水平安裝。

先導(dao)式電磁(ci)閥(fa)

原理(li)：通(tong)(tong)電時，電磁力(li)(li)把先(xian)導孔(kong)打(da)開，上(shang)(shang)腔室壓力(li)(li)迅速下(xia)(xia)降，在關(guan) 閉(bi)件周(zhou)圍形(xing)成(cheng)上(shang)(shang)低下(xia)(xia)高(gao)的壓差，流(liu)體(ti)壓力(li)(li)推動(dong)(dong)關(guan)閉(bi)件向上(shang)(shang)移動(dong)(dong)，閥(fa)門打(da)開；斷電時，彈簧(huang)力(li)(li)把先(xian)導孔(kong)關(guan)閉(bi)，入口壓力(li)(li)通(tong)(tong)過旁通(tong)(tong)孔(kong)迅速腔室在關(guan)閥(fa)件周(zhou)圍形(xing)成(cheng)下(xia)(xia)低上(shang)(shang)高(gao)的壓差，流(liu)體(ti)壓力(li)(li)推動(dong)(dong)關(guan)閉(bi)件向下(xia)(xia)移動(dong)(dong)，關(guan)閉(bi)閥(fa)門。

特點：流體(ti)壓力范圍上限較高，可任意安裝（需定制）但必須(xu)滿足流體(ti)壓差(cha)條件。

2、電磁閥從閥結(jie)構(gou)和材料上的(de)不同與原理上的(de)區別，分為六個分支小類(lei)：直(zhi)動(dong)膜片(pian)結(jie)構(gou)、分步(bu)直(zhi)動(dong)膜片(pian)結(jie)構(gou)、先導膜片(pian)結(jie)構(gou)、直(zhi)動(dong)活(huo)塞結(jie)構(gou)、分步(bu)直(zhi)動(dong)活(huo)塞結(jie)構(gou)、先導活(huo)塞結(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)按(an)照(zhao)功能(neng)分類：水(shui)用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、蒸汽(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)等。