電(dian)(dian)磁(ci)閥(fa)（Electromagnetic valve）是用(yong)電(dian)(dian)磁(ci)控(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)工業(ye)設備(bei)，是用(yong)來控(kong)制(zhi)(zhi)(zhi)流體的(de)(de)(de)自(zi)動(dong)化基礎元件，屬于執行器，并不限于液壓(ya)、氣動(dong)。用(yong)在(zai)工業(ye)控(kong)制(zhi)(zhi)(zhi)系統中(zhong)調整介質的(de)(de)(de)方向、流量、速度和(he)其他的(de)(de)(de)參數。電(dian)(dian)磁(ci)閥(fa)可以配合(he)不同(tong)(tong)(tong)的(de)(de)(de)電(dian)(dian)路來實現預期(qi)的(de)(de)(de)控(kong)制(zhi)(zhi)(zhi)，而控(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)精度和(he)靈(ling)活(huo)性(xing)都(dou)能夠(gou)保(bao)證。電(dian)(dian)磁(ci)閥(fa)有(you)很多種，不同(tong)(tong)(tong)的(de)(de)(de)電(dian)(dian)磁(ci)閥(fa)在(zai)控(kong)制(zhi)(zhi)(zhi)系統的(de)(de)(de)不同(tong)(tong)(tong)位(wei)置發揮作用(yong)，最常(chang)用(yong)的(de)(de)(de)是單向閥(fa)、安全閥(fa)、方向控(kong)制(zhi)(zhi)(zhi)閥(fa)、速度調節(jie)閥(fa)等。

電磁(ci)閥(fa)(fa)里有(you)密閉的(de)(de)(de)(de)(de)(de)腔，在不(bu)同(tong)(tong)位置(zhi)開有(you)通(tong)孔(kong)，每個孔(kong)連接不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)(de)油(you)(you)管(guan)，腔中(zhong)間是(shi)(shi)活塞，兩(liang)(liang)面是(shi)(shi)兩(liang)(liang)塊電磁(ci)鐵，哪面的(de)(de)(de)(de)(de)(de)磁(ci)鐵線圈(quan)通(tong)電閥(fa)(fa)體就會被吸引(yin)到哪邊，通(tong)過控制閥(fa)(fa)體的(de)(de)(de)(de)(de)(de)移動來開啟或關閉不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)(de)排油(you)(you)孔(kong)，而(er)進油(you)(you)孔(kong)是(shi)(shi)常開的(de)(de)(de)(de)(de)(de)，液壓油(you)(you)就會進入(ru)不(bu)同(tong)(tong)的(de)(de)(de)(de)(de)(de)排油(you)(you)管(guan)，然(ran)后通(tong)過油(you)(you)的(de)(de)(de)(de)(de)(de)壓力來推動油(you)(you)缸的(de)(de)(de)(de)(de)(de)活塞，活塞又帶動活塞桿(gan)，活塞桿(gan)帶動機(ji)械裝(zhuang)置(zhi)。這(zhe)樣(yang)通(tong)過控制電磁(ci)鐵的(de)(de)(de)(de)(de)(de)電流通(tong)斷就控制了機(ji)械運動。

1、電磁閥從原理上分為三大類：

直動(dong)式電(dian)磁閥

原理(li)：通電時，電磁線圈產生(sheng)電磁力(li)把關閉件從閥(fa)座上提起(qi)，閥(fa)門打開(kai)；斷電時，電磁力(li)消失，彈簧(huang)把關閉件壓在閥(fa)座上，閥(fa)門關閉。

特(te)點(dian)：在真空、負壓(ya)、零(ling)壓(ya)時能正常工(gong)作，但通徑一(yi)般不超過25mm。

分步直動式電磁(ci)閥

原理：它是(shi)一種(zhong)直動(dong)和先(xian)(xian)導(dao)(dao)式相結合(he)的原理，當入(ru)口與(yu)出口沒有壓(ya)(ya)(ya)差(cha)(cha)時(shi)(shi)，通電(dian)(dian)后(hou)，電(dian)(dian)磁(ci)力(li)(li)直接把先(xian)(xian)導(dao)(dao)小閥(fa)和主閥(fa)關(guan)(guan)閉件依(yi)次向上(shang)提(ti)起(qi)，閥(fa)門(men)(men)打(da)開。當入(ru)口與(yu)出口達到啟(qi)動(dong)壓(ya)(ya)(ya)差(cha)(cha)時(shi)(shi)，通電(dian)(dian)后(hou)，電(dian)(dian)磁(ci)力(li)(li)先(xian)(xian)導(dao)(dao)小閥(fa)，主閥(fa)下腔壓(ya)(ya)(ya)力(li)(li)上(shang)升(sheng)，上(shang)腔壓(ya)(ya)(ya)力(li)(li)下降，從而(er)利(li)用壓(ya)(ya)(ya)差(cha)(cha)把主閥(fa)向上(shang)推開；斷電(dian)(dian)時(shi)(shi)，先(xian)(xian)導(dao)(dao)閥(fa)利(li)用彈簧(huang)力(li)(li)或介質(zhi)壓(ya)(ya)(ya)力(li)(li)推動(dong)關(guan)(guan)閉件，向下移動(dong)，使(shi)閥(fa)門(men)(men)關(guan)(guan)閉。

特點(dian)：在零(ling)壓差(cha)或(huo)真(zhen)空、高(gao)壓時(shi)亦(yi)能可*動作，但功率較(jiao)大，要求必須水平(ping)安裝。

先導式電磁閥(fa)

原理：通電時，電磁力(li)把先導(dao)孔打開(kai)，上腔(qiang)(qiang)室壓(ya)(ya)(ya)力(li)迅速下(xia)(xia)(xia)降，在(zai)關(guan)(guan) 閉(bi)件(jian)周(zhou)圍形成上低下(xia)(xia)(xia)高的(de)壓(ya)(ya)(ya)差，流體(ti)(ti)壓(ya)(ya)(ya)力(li)推動關(guan)(guan)閉(bi)件(jian)向上移動，閥(fa)門(men)(men)打開(kai)；斷電時，彈簧力(li)把先導(dao)孔關(guan)(guan)閉(bi)，入(ru)口壓(ya)(ya)(ya)力(li)通過(guo)旁通孔迅速腔(qiang)(qiang)室在(zai)關(guan)(guan)閥(fa)件(jian)周(zhou)圍形成下(xia)(xia)(xia)低上高的(de)壓(ya)(ya)(ya)差，流體(ti)(ti)壓(ya)(ya)(ya)力(li)推動關(guan)(guan)閉(bi)件(jian)向下(xia)(xia)(xia)移動，關(guan)(guan)閉(bi)閥(fa)門(men)(men)。

特點：流體(ti)壓力范圍(wei)上(shang)限較高(gao)，可任意安(an)裝（需定制）但必須滿足流體(ti)壓差(cha)條件。

2、電磁閥(fa)從閥(fa)結(jie)(jie)構(gou)(gou)和材(cai)料上的(de)不同與原理上的(de)區別，分為六(liu)個分支小類：直(zhi)動膜(mo)片結(jie)(jie)構(gou)(gou)、分步直(zhi)動膜(mo)片結(jie)(jie)構(gou)(gou)、先(xian)導膜(mo)片結(jie)(jie)構(gou)(gou)、直(zhi)動活塞(sai)結(jie)(jie)構(gou)(gou)、分步直(zhi)動活塞(sai)結(jie)(jie)構(gou)(gou)、先(xian)導活塞(sai)結(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按照(zhao)功能(neng)分類：水用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃(ran)氣(qi)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣(qi)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微(wei)(wei)型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖(chong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常(chang)開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等(deng)。