電(dian)(dian)磁(ci)閥(fa)（Electromagnetic valve）是用(yong)電(dian)(dian)磁(ci)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)工業設備(bei)，是用(yong)來控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)流體的(de)(de)(de)自動化基礎元(yuan)件，屬于(yu)執行(xing)器，并(bing)不限于(yu)液(ye)壓(ya)、氣動。用(yong)在工業控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系統中(zhong)調(diao)整(zheng)介(jie)質的(de)(de)(de)方(fang)向、流量(liang)、速度(du)和(he)其他(ta)的(de)(de)(de)參數。電(dian)(dian)磁(ci)閥(fa)可以配(pei)合不同(tong)的(de)(de)(de)電(dian)(dian)路來實現預期的(de)(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)精(jing)度(du)和(he)靈活性都(dou)能夠保證。電(dian)(dian)磁(ci)閥(fa)有(you)很多(duo)種(zhong)，不同(tong)的(de)(de)(de)電(dian)(dian)磁(ci)閥(fa)在控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系統的(de)(de)(de)不同(tong)位置發揮作用(yong)，最(zui)常用(yong)的(de)(de)(de)是單(dan)向閥(fa)、安全閥(fa)、方(fang)向控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)閥(fa)、速度(du)調(diao)節閥(fa)等。

電(dian)(dian)(dian)磁閥里有(you)密閉的(de)(de)腔，在不同(tong)位置(zhi)開有(you)通孔，每個孔連接不同(tong)的(de)(de)油(you)管(guan)，腔中間是活(huo)塞，兩(liang)面(mian)是兩(liang)塊電(dian)(dian)(dian)磁鐵(tie)，哪面(mian)的(de)(de)磁鐵(tie)線圈通電(dian)(dian)(dian)閥體就會(hui)被吸引(yin)到哪邊，通過(guo)控制(zhi)閥體的(de)(de)移動(dong)來開啟或(huo)關(guan)閉不同(tong)的(de)(de)排(pai)油(you)孔，而進油(you)孔是常開的(de)(de)，液壓(ya)油(you)就會(hui)進入不同(tong)的(de)(de)排(pai)油(you)管(guan)，然后通過(guo)油(you)的(de)(de)壓(ya)力來推(tui)動(dong)油(you)缸的(de)(de)活(huo)塞，活(huo)塞又帶(dai)動(dong)活(huo)塞桿，活(huo)塞桿帶(dai)動(dong)機械裝置(zhi)。這(zhe)樣通過(guo)控制(zhi)電(dian)(dian)(dian)磁鐵(tie)的(de)(de)電(dian)(dian)(dian)流通斷就控制(zhi)了機械運(yun)動(dong)。

1、電磁閥從(cong)原理上分為三(san)大類：

直動(dong)式電磁閥(fa)

原理：通電(dian)(dian)時，電(dian)(dian)磁線圈產(chan)生電(dian)(dian)磁力把關閉件從(cong)閥(fa)(fa)座上(shang)提起，閥(fa)(fa)門打開；斷電(dian)(dian)時，電(dian)(dian)磁力消失，彈簧(huang)把關閉件壓在閥(fa)(fa)座上(shang)，閥(fa)(fa)門關閉。

特點：在真空(kong)、負壓(ya)、零壓(ya)時能正常工(gong)作，但通徑(jing)一(yi)般不(bu)超過25mm。

分步(bu)直動式電磁閥(fa)

原理(li)：它(ta)是一(yi)種(zhong)直(zhi)(zhi)動和(he)先導(dao)式相結合的原理(li)，當入口(kou)與出口(kou)沒有壓(ya)差(cha)(cha)時(shi)，通(tong)電(dian)(dian)后，電(dian)(dian)磁力(li)直(zhi)(zhi)接把先導(dao)小閥和(he)主閥關閉件(jian)依次(ci)向(xiang)上提(ti)起，閥門打(da)開。當入口(kou)與出口(kou)達到(dao)啟動壓(ya)差(cha)(cha)時(shi)，通(tong)電(dian)(dian)后，電(dian)(dian)磁力(li)先導(dao)小閥，主閥下腔壓(ya)力(li)上升，上腔壓(ya)力(li)下降，從(cong)而利(li)用壓(ya)差(cha)(cha)把主閥向(xiang)上推開；斷電(dian)(dian)時(shi)，先導(dao)閥利(li)用彈簧力(li)或介質壓(ya)力(li)推動關閉件(jian)，向(xiang)下移動，使閥門關閉。

特點：在零(ling)壓(ya)差(cha)或(huo)真(zhen)空、高(gao)壓(ya)時亦能可*動作，但功率較大，要求(qiu)必(bi)須水平(ping)安裝。

先導(dao)式電磁閥

原(yuan)理：通(tong)電(dian)(dian)時，電(dian)(dian)磁力(li)把先導孔(kong)打開，上(shang)(shang)腔(qiang)室(shi)壓(ya)力(li)迅(xun)速下降，在關(guan)(guan) 閉(bi)件周圍形成上(shang)(shang)低下高的壓(ya)差(cha)，流(liu)體(ti)壓(ya)力(li)推(tui)動(dong)關(guan)(guan)閉(bi)件向上(shang)(shang)移(yi)動(dong)，閥門(men)打開；斷電(dian)(dian)時，彈簧力(li)把先導孔(kong)關(guan)(guan)閉(bi)，入(ru)口壓(ya)力(li)通(tong)過旁通(tong)孔(kong)迅(xun)速腔(qiang)室(shi)在關(guan)(guan)閥件周圍形成下低上(shang)(shang)高的壓(ya)差(cha)，流(liu)體(ti)壓(ya)力(li)推(tui)動(dong)關(guan)(guan)閉(bi)件向下移(yi)動(dong)，關(guan)(guan)閉(bi)閥門(men)。

特點(dian)：流體壓(ya)力范圍上限較高(gao)，可任意安裝(zhuang)（需(xu)定制）但必(bi)須(xu)滿足流體壓(ya)差條件。

2、電磁閥(fa)從(cong)閥(fa)結(jie)(jie)構(gou)和材料上(shang)的不同與原理上(shang)的區別，分為六個分支小類：直動(dong)(dong)(dong)膜(mo)片(pian)結(jie)(jie)構(gou)、分步(bu)(bu)直動(dong)(dong)(dong)膜(mo)片(pian)結(jie)(jie)構(gou)、先導膜(mo)片(pian)結(jie)(jie)構(gou)、直動(dong)(dong)(dong)活(huo)(huo)塞結(jie)(jie)構(gou)、分步(bu)(bu)直動(dong)(dong)(dong)活(huo)(huo)塞結(jie)(jie)構(gou)、先導活(huo)(huo)塞結(jie)(jie)構(gou)。

3、電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按照(zhao)功能分(fen)類：水用電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸(zheng)汽電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消(xiao)防(fang)電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣體電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液體電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微(wei)型電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖(chong)電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液壓電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常開(kai)電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直(zhi)流電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防(fang)爆電(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等。