電(dian)磁(ci)(ci)閥(fa)(fa)（Electromagnetic valve）是用(yong)(yong)(yong)(yong)電(dian)磁(ci)(ci)控(kong)制(zhi)的(de)工(gong)業設備，是用(yong)(yong)(yong)(yong)來控(kong)制(zhi)流體的(de)自動(dong)(dong)化基(ji)礎元件，屬于(yu)執行器，并不限(xian)于(yu)液壓、氣(qi)動(dong)(dong)。用(yong)(yong)(yong)(yong)在工(gong)業控(kong)制(zhi)系統中調(diao)整介質(zhi)的(de)方(fang)向(xiang)、流量(liang)、速(su)度和(he)(he)其他的(de)參數。電(dian)磁(ci)(ci)閥(fa)(fa)可以配(pei)合(he)不同的(de)電(dian)路(lu)來實現預期的(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)精度和(he)(he)靈活性都能夠保證(zheng)。電(dian)磁(ci)(ci)閥(fa)(fa)有很多種，不同的(de)電(dian)磁(ci)(ci)閥(fa)(fa)在控(kong)制(zhi)系統的(de)不同位置發揮作用(yong)(yong)(yong)(yong)，最常用(yong)(yong)(yong)(yong)的(de)是單向(xiang)閥(fa)(fa)、安全閥(fa)(fa)、方(fang)向(xiang)控(kong)制(zhi)閥(fa)(fa)、速(su)度調(diao)節閥(fa)(fa)等。

電(dian)(dian)(dian)磁(ci)閥里有密閉的(de)(de)腔(qiang)，在(zai)不同位置開(kai)有通孔(kong)，每個孔(kong)連(lian)接不同的(de)(de)油(you)(you)管，腔(qiang)中(zhong)間是活(huo)(huo)(huo)塞，兩面是兩塊電(dian)(dian)(dian)磁(ci)鐵(tie)，哪面的(de)(de)磁(ci)鐵(tie)線圈(quan)通電(dian)(dian)(dian)閥體就(jiu)會(hui)被吸引到哪邊，通過(guo)(guo)(guo)控(kong)制閥體的(de)(de)移動(dong)來開(kai)啟或關(guan)閉不同的(de)(de)排油(you)(you)孔(kong)，而(er)進油(you)(you)孔(kong)是常開(kai)的(de)(de)，液壓油(you)(you)就(jiu)會(hui)進入不同的(de)(de)排油(you)(you)管，然后通過(guo)(guo)(guo)油(you)(you)的(de)(de)壓力(li)來推動(dong)油(you)(you)缸的(de)(de)活(huo)(huo)(huo)塞，活(huo)(huo)(huo)塞又帶動(dong)活(huo)(huo)(huo)塞桿，活(huo)(huo)(huo)塞桿帶動(dong)機械裝(zhuang)置。這樣通過(guo)(guo)(guo)控(kong)制電(dian)(dian)(dian)磁(ci)鐵(tie)的(de)(de)電(dian)(dian)(dian)流通斷就(jiu)控(kong)制了機械運動(dong)。

1、電(dian)磁閥(fa)從原理上分(fen)為三(san)大類：

直動式電磁閥

原理：通(tong)電(dian)(dian)時，電(dian)(dian)磁(ci)線圈產生電(dian)(dian)磁(ci)力把關(guan)閉(bi)件從閥座(zuo)(zuo)上(shang)提起，閥門打(da)開；斷電(dian)(dian)時，電(dian)(dian)磁(ci)力消失，彈簧(huang)把關(guan)閉(bi)件壓(ya)在閥座(zuo)(zuo)上(shang)，閥門關(guan)閉(bi)。

特(te)點：在(zai)真空、負壓、零壓時(shi)能(neng)正常工作，但(dan)通徑一般不超(chao)過25mm。

分步(bu)直(zhi)動式電(dian)磁閥

原理：它是一種直(zhi)動(dong)(dong)和(he)(he)先導(dao)(dao)式(shi)相結合的原理，當(dang)入口與出口沒有壓(ya)(ya)差(cha)時，通電后(hou)，電磁力直(zhi)接把先導(dao)(dao)小閥(fa)和(he)(he)主(zhu)(zhu)閥(fa)關閉(bi)件(jian)依次向(xiang)上(shang)提起，閥(fa)門打(da)開。當(dang)入口與出口達到啟動(dong)(dong)壓(ya)(ya)差(cha)時，通電后(hou)，電磁力先導(dao)(dao)小閥(fa)，主(zhu)(zhu)閥(fa)下(xia)腔壓(ya)(ya)力上(shang)升(sheng)，上(shang)腔壓(ya)(ya)力下(xia)降(jiang)，從而(er)利用壓(ya)(ya)差(cha)把主(zhu)(zhu)閥(fa)向(xiang)上(shang)推(tui)開；斷電時，先導(dao)(dao)閥(fa)利用彈(dan)簧(huang)力或介質壓(ya)(ya)力推(tui)動(dong)(dong)關閉(bi)件(jian)，向(xiang)下(xia)移動(dong)(dong)，使閥(fa)門關閉(bi)。

特點：在(zai)零壓差或真空、高(gao)壓時(shi)亦(yi)能可(ke)*動作，但功率較大，要求必須水平安裝(zhuang)。

先導(dao)式電磁(ci)閥

原理：通(tong)電(dian)時，電(dian)磁力(li)(li)(li)把先導(dao)孔(kong)打開，上(shang)腔室壓(ya)(ya)力(li)(li)(li)迅(xun)速下(xia)降，在(zai)關 閉(bi)件(jian)周圍形(xing)(xing)成上(shang)低(di)(di)下(xia)高(gao)的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力(li)(li)(li)推動關閉(bi)件(jian)向(xiang)上(shang)移(yi)(yi)動，閥(fa)(fa)門打開；斷電(dian)時，彈簧力(li)(li)(li)把先導(dao)孔(kong)關閉(bi)，入口壓(ya)(ya)力(li)(li)(li)通(tong)過旁(pang)通(tong)孔(kong)迅(xun)速腔室在(zai)關閥(fa)(fa)件(jian)周圍形(xing)(xing)成下(xia)低(di)(di)上(shang)高(gao)的壓(ya)(ya)差，流(liu)體壓(ya)(ya)力(li)(li)(li)推動關閉(bi)件(jian)向(xiang)下(xia)移(yi)(yi)動，關閉(bi)閥(fa)(fa)門。

特點：流體(ti)壓(ya)力范圍上限較高，可任(ren)意安裝(zhuang)（需定制）但必須滿足流體(ti)壓(ya)差條件(jian)。

2、電磁閥從(cong)閥結(jie)(jie)構(gou)和(he)材料上的不同與原理上的區(qu)別，分(fen)為六個分(fen)支小(xiao)類：直(zhi)動膜片(pian)(pian)結(jie)(jie)構(gou)、分(fen)步(bu)直(zhi)動膜片(pian)(pian)結(jie)(jie)構(gou)、先導膜片(pian)(pian)結(jie)(jie)構(gou)、直(zhi)動活塞結(jie)(jie)構(gou)、分(fen)步(bu)直(zhi)動活塞結(jie)(jie)構(gou)、先導活塞結(jie)(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)按(an)照功能分類：水用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、消防(fang)電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氨用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氣體(ti)(ti)電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液體(ti)(ti)電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、微型電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、脈(mo)沖電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液壓電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa) 常(chang)開電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、油用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、直流電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)、防(fang)爆電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)等。