電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是用電(dian)磁(ci)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)工業(ye)設備(bei)，是用來控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)流體的(de)自動(dong)化(hua)基(ji)礎元(yuan)件(jian)，屬于(yu)執行(xing)器(qi)，并(bing)不限于(yu)液壓(ya)、氣動(dong)。用在(zai)工業(ye)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系(xi)統中調(diao)整介質的(de)方向(xiang)、流量、速度和(he)(he)其他(ta)的(de)參數。電(dian)磁(ci)閥(fa)(fa)可(ke)以配合(he)不同(tong)的(de)電(dian)路(lu)來實現預期(qi)的(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)精度和(he)(he)靈活性都能(neng)夠保證。電(dian)磁(ci)閥(fa)(fa)有很多種，不同(tong)的(de)電(dian)磁(ci)閥(fa)(fa)在(zai)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系(xi)統的(de)不同(tong)位置(zhi)發(fa)揮作用，最常(chang)用的(de)是單向(xiang)閥(fa)(fa)、安全閥(fa)(fa)、方向(xiang)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)閥(fa)(fa)、速度調(diao)節閥(fa)(fa)等。

電(dian)(dian)磁閥里有(you)密閉(bi)的(de)(de)腔，在(zai)不同(tong)位置開(kai)有(you)通孔，每個孔連(lian)接不同(tong)的(de)(de)油(you)管，腔中(zhong)間是活塞(sai)，兩面是兩塊電(dian)(dian)磁鐵(tie)(tie)，哪(na)面的(de)(de)磁鐵(tie)(tie)線圈通電(dian)(dian)閥體就會(hui)被吸引(yin)到哪(na)邊(bian)，通過控制閥體的(de)(de)移動(dong)(dong)來開(kai)啟或關閉(bi)不同(tong)的(de)(de)排(pai)(pai)油(you)孔，而進油(you)孔是常(chang)開(kai)的(de)(de)，液壓油(you)就會(hui)進入不同(tong)的(de)(de)排(pai)(pai)油(you)管，然后通過油(you)的(de)(de)壓力來推(tui)動(dong)(dong)油(you)缸的(de)(de)活塞(sai)，活塞(sai)又帶動(dong)(dong)活塞(sai)桿，活塞(sai)桿帶動(dong)(dong)機械裝置。這樣通過控制電(dian)(dian)磁鐵(tie)(tie)的(de)(de)電(dian)(dian)流通斷就控制了機械運動(dong)(dong)。

1、電磁閥從原理(li)上分為三(san)大類：

直動式電磁(ci)閥

原理(li)：通電(dian)時，電(dian)磁線(xian)圈產生電(dian)磁力(li)把關閉件從閥座上提起，閥門(men)打開；斷電(dian)時，電(dian)磁力(li)消失，彈簧把關閉件壓在閥座上，閥門(men)關閉。

特點：在真(zhen)空(kong)、負(fu)壓、零壓時能(neng)正常(chang)工作，但通徑一般不超過25mm。

分步直動式電磁(ci)閥

原(yuan)理：它是一種(zhong)直(zhi)動(dong)和先導式(shi)相結合的原(yuan)理，當(dang)入(ru)口(kou)與出(chu)口(kou)沒(mei)有壓(ya)(ya)(ya)(ya)差(cha)時(shi)，通電(dian)(dian)后，電(dian)(dian)磁力直(zhi)接把(ba)先導小閥和主閥關閉件(jian)依次向上(shang)提起，閥門(men)打開。當(dang)入(ru)口(kou)與出(chu)口(kou)達到啟動(dong)壓(ya)(ya)(ya)(ya)差(cha)時(shi)，通電(dian)(dian)后，電(dian)(dian)磁力先導小閥，主閥下(xia)(xia)腔(qiang)壓(ya)(ya)(ya)(ya)力上(shang)升(sheng)，上(shang)腔(qiang)壓(ya)(ya)(ya)(ya)力下(xia)(xia)降，從而利(li)用壓(ya)(ya)(ya)(ya)差(cha)把(ba)主閥向上(shang)推開；斷(duan)電(dian)(dian)時(shi)，先導閥利(li)用彈簧力或(huo)介質壓(ya)(ya)(ya)(ya)力推動(dong)關閉件(jian)，向下(xia)(xia)移動(dong)，使閥門(men)關閉。

特點：在(zai)零(ling)壓(ya)差或真(zhen)空、高壓(ya)時亦能可*動作(zuo)，但功(gong)率(lv)較(jiao)大，要(yao)求必須水(shui)平安裝。

先導式電磁(ci)閥

原理：通電(dian)時，電(dian)磁力(li)把先導孔(kong)打開，上(shang)腔室(shi)壓力(li)迅速(su)(su)下降(jiang)，在(zai)(zai)關(guan)(guan)(guan) 閉(bi)件周圍形(xing)成上(shang)低下高的(de)壓差，流(liu)體(ti)(ti)壓力(li)推動(dong)關(guan)(guan)(guan)閉(bi)件向上(shang)移動(dong)，閥(fa)門打開；斷電(dian)時，彈(dan)簧力(li)把先導孔(kong)關(guan)(guan)(guan)閉(bi)，入口壓力(li)通過(guo)旁通孔(kong)迅速(su)(su)腔室(shi)在(zai)(zai)關(guan)(guan)(guan)閥(fa)件周圍形(xing)成下低上(shang)高的(de)壓差，流(liu)體(ti)(ti)壓力(li)推動(dong)關(guan)(guan)(guan)閉(bi)件向下移動(dong)，關(guan)(guan)(guan)閉(bi)閥(fa)門。

特點(dian)：流體(ti)壓(ya)力范(fan)圍上(shang)限較高，可任(ren)意(yi)安裝（需定制）但必(bi)須滿足流體(ti)壓(ya)差條件(jian)。

2、電磁閥從閥結(jie)(jie)構(gou)(gou)和(he)材料上的(de)不同與原理上的(de)區別，分(fen)為六(liu)個分(fen)支小類：直動(dong)(dong)膜(mo)(mo)片(pian)結(jie)(jie)構(gou)(gou)、分(fen)步直動(dong)(dong)膜(mo)(mo)片(pian)結(jie)(jie)構(gou)(gou)、先導膜(mo)(mo)片(pian)結(jie)(jie)構(gou)(gou)、直動(dong)(dong)活(huo)(huo)塞結(jie)(jie)構(gou)(gou)、分(fen)步直動(dong)(dong)活(huo)(huo)塞結(jie)(jie)構(gou)(gou)、先導活(huo)(huo)塞結(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按照功能分類：水用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣(qi)體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)(ye)體(ti)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)(ye)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等。