電(dian)(dian)磁閥(fa)(fa)（Electromagnetic valve）是(shi)用(yong)電(dian)(dian)磁控(kong)制(zhi)(zhi)的(de)工業(ye)設備(bei)，是(shi)用(yong)來控(kong)制(zhi)(zhi)流體(ti)的(de)自動(dong)化(hua)基礎元(yuan)件(jian)，屬于執行器，并不(bu)(bu)限于液壓、氣(qi)動(dong)。用(yong)在(zai)工業(ye)控(kong)制(zhi)(zhi)系(xi)統中(zhong)調整介質的(de)方(fang)向、流量、速度和其他(ta)的(de)參數。電(dian)(dian)磁閥(fa)(fa)可以配合不(bu)(bu)同(tong)(tong)的(de)電(dian)(dian)路來實現(xian)預期的(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)精度和靈活性都能夠(gou)保證(zheng)。電(dian)(dian)磁閥(fa)(fa)有很(hen)多種，不(bu)(bu)同(tong)(tong)的(de)電(dian)(dian)磁閥(fa)(fa)在(zai)控(kong)制(zhi)(zhi)系(xi)統的(de)不(bu)(bu)同(tong)(tong)位置發揮作用(yong)，最常(chang)用(yong)的(de)是(shi)單向閥(fa)(fa)、安全閥(fa)(fa)、方(fang)向控(kong)制(zhi)(zhi)閥(fa)(fa)、速度調節閥(fa)(fa)等。

電(dian)磁閥里有密閉(bi)的(de)(de)腔(qiang)，在不(bu)同位置開有通(tong)孔(kong)，每個孔(kong)連接不(bu)同的(de)(de)油(you)(you)管(guan)，腔(qiang)中間是(shi)活(huo)塞(sai)，兩面是(shi)兩塊電(dian)磁鐵(tie)，哪面的(de)(de)磁鐵(tie)線圈通(tong)電(dian)閥體(ti)就會(hui)被吸引(yin)到哪邊(bian)，通(tong)過(guo)(guo)控制閥體(ti)的(de)(de)移(yi)動(dong)來開啟或關閉(bi)不(bu)同的(de)(de)排油(you)(you)孔(kong)，而進(jin)油(you)(you)孔(kong)是(shi)常開的(de)(de)，液(ye)壓油(you)(you)就會(hui)進(jin)入不(bu)同的(de)(de)排油(you)(you)管(guan)，然后通(tong)過(guo)(guo)油(you)(you)的(de)(de)壓力來推(tui)動(dong)油(you)(you)缸(gang)的(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又帶(dai)動(dong)活(huo)塞(sai)桿(gan)，活(huo)塞(sai)桿(gan)帶(dai)動(dong)機(ji)械裝置。這樣(yang)通(tong)過(guo)(guo)控制電(dian)磁鐵(tie)的(de)(de)電(dian)流通(tong)斷就控制了機(ji)械運動(dong)。

1、電磁閥從原理上(shang)分為三大類：

直動式電(dian)磁閥

原理：通電(dian)(dian)時，電(dian)(dian)磁線圈產(chan)生電(dian)(dian)磁力(li)把關閉件(jian)從閥(fa)座上提起(qi)，閥(fa)門打開(kai)；斷(duan)電(dian)(dian)時，電(dian)(dian)磁力(li)消失(shi)，彈簧把關閉件(jian)壓在閥(fa)座上，閥(fa)門關閉。

特點：在真空(kong)、負壓、零(ling)壓時能正常(chang)工作，但通徑一般不(bu)超過25mm。

分步直(zhi)動(dong)式電(dian)磁閥

原理(li)(li)：它是一種直動和(he)先(xian)(xian)導式相結合的原理(li)(li)，當入口與(yu)(yu)出(chu)口沒(mei)有壓差(cha)(cha)時，通(tong)電后，電磁力直接(jie)把先(xian)(xian)導小(xiao)閥和(he)主閥關閉件(jian)依次向上提起，閥門打(da)開(kai)。當入口與(yu)(yu)出(chu)口達(da)到啟動壓差(cha)(cha)時，通(tong)電后，電磁力先(xian)(xian)導小(xiao)閥，主閥下(xia)腔(qiang)壓力上升，上腔(qiang)壓力下(xia)降，從而利(li)用壓差(cha)(cha)把主閥向上推(tui)開(kai)；斷電時，先(xian)(xian)導閥利(li)用彈(dan)簧(huang)力或(huo)介質壓力推(tui)動關閉件(jian)，向下(xia)移動，使閥門關閉。

特點：在零壓差(cha)或真空、高壓時亦能可*動(dong)作，但功(gong)率較大，要求必(bi)須(xu)水平安裝。

先導式(shi)電磁閥(fa)

原(yuan)理：通電時，電磁力把(ba)先導(dao)孔打開，上(shang)(shang)腔(qiang)室(shi)壓(ya)(ya)力迅速下降，在關(guan) 閉(bi)件(jian)周圍形(xing)成上(shang)(shang)低下高(gao)(gao)的壓(ya)(ya)差，流體(ti)(ti)壓(ya)(ya)力推動關(guan)閉(bi)件(jian)向上(shang)(shang)移動，閥(fa)門打開；斷電時，彈簧(huang)力把(ba)先導(dao)孔關(guan)閉(bi)，入口(kou)壓(ya)(ya)力通過旁(pang)通孔迅速腔(qiang)室(shi)在關(guan)閥(fa)件(jian)周圍形(xing)成下低上(shang)(shang)高(gao)(gao)的壓(ya)(ya)差，流體(ti)(ti)壓(ya)(ya)力推動關(guan)閉(bi)件(jian)向下移動，關(guan)閉(bi)閥(fa)門。

特點(dian)：流體(ti)壓力范圍上限較高(gao)，可任(ren)意安裝（需定制）但必(bi)須滿足流體(ti)壓差條件。

2、電磁閥從(cong)閥結(jie)(jie)構(gou)(gou)和材料(liao)上的不(bu)同與原理上的區別，分為六(liu)個分支(zhi)小(xiao)類：直(zhi)動(dong)(dong)膜(mo)片(pian)(pian)結(jie)(jie)構(gou)(gou)、分步(bu)直(zhi)動(dong)(dong)膜(mo)片(pian)(pian)結(jie)(jie)構(gou)(gou)、先(xian)(xian)導(dao)膜(mo)片(pian)(pian)結(jie)(jie)構(gou)(gou)、直(zhi)動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)、分步(bu)直(zhi)動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)、先(xian)(xian)導(dao)活(huo)塞(sai)(sai)結(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)按照(zhao)功能分類：水(shui)用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、制(zhi)冷(leng)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、低(di)溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、燃氣(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氣(qi)(qi)體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)等。