電磁(ci)閥（Electromagnetic valve）是(shi)用(yong)電磁(ci)控(kong)制(zhi)(zhi)的(de)工業設備，是(shi)用(yong)來控(kong)制(zhi)(zhi)流體(ti)的(de)自動化基(ji)礎(chu)元件，屬于(yu)執行器，并不限于(yu)液(ye)壓、氣(qi)動。用(yong)在(zai)工業控(kong)制(zhi)(zhi)系統(tong)中(zhong)調(diao)整介(jie)質的(de)方(fang)向(xiang)、流量、速度(du)和其(qi)他的(de)參數。電磁(ci)閥可以(yi)配合不同(tong)的(de)電路(lu)來實現預期的(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)精度(du)和靈活性都(dou)能夠保證。電磁(ci)閥有很多種，不同(tong)的(de)電磁(ci)閥在(zai)控(kong)制(zhi)(zhi)系統(tong)的(de)不同(tong)位置發揮作(zuo)用(yong)，最(zui)常用(yong)的(de)是(shi)單向(xiang)閥、安全(quan)閥、方(fang)向(xiang)控(kong)制(zhi)(zhi)閥、速度(du)調(diao)節閥等。

電(dian)(dian)磁(ci)閥里有密閉(bi)的(de)(de)(de)腔，在不(bu)同位(wei)置(zhi)開有通(tong)(tong)孔，每個(ge)孔連接不(bu)同的(de)(de)(de)油(you)(you)(you)管，腔中間是活(huo)(huo)塞(sai)(sai)，兩(liang)(liang)面(mian)是兩(liang)(liang)塊電(dian)(dian)磁(ci)鐵(tie)，哪(na)面(mian)的(de)(de)(de)磁(ci)鐵(tie)線圈通(tong)(tong)電(dian)(dian)閥體就(jiu)會(hui)被吸引到哪(na)邊，通(tong)(tong)過(guo)(guo)(guo)控制閥體的(de)(de)(de)移動來開啟或關(guan)閉(bi)不(bu)同的(de)(de)(de)排油(you)(you)(you)孔，而(er)進油(you)(you)(you)孔是常(chang)開的(de)(de)(de)，液壓油(you)(you)(you)就(jiu)會(hui)進入不(bu)同的(de)(de)(de)排油(you)(you)(you)管，然后通(tong)(tong)過(guo)(guo)(guo)油(you)(you)(you)的(de)(de)(de)壓力來推動油(you)(you)(you)缸的(de)(de)(de)活(huo)(huo)塞(sai)(sai)，活(huo)(huo)塞(sai)(sai)又帶動活(huo)(huo)塞(sai)(sai)桿，活(huo)(huo)塞(sai)(sai)桿帶動機械裝置(zhi)。這樣通(tong)(tong)過(guo)(guo)(guo)控制電(dian)(dian)磁(ci)鐵(tie)的(de)(de)(de)電(dian)(dian)流通(tong)(tong)斷(duan)就(jiu)控制了機械運動。

1、電磁閥從原理上分為三大類：

直動式(shi)電磁閥

原理：通(tong)電(dian)時，電(dian)磁線圈產生電(dian)磁力把(ba)關(guan)閉件從閥(fa)座上提起，閥(fa)門(men)打開；斷電(dian)時，電(dian)磁力消失(shi)，彈(dan)簧把(ba)關(guan)閉件壓在閥(fa)座上，閥(fa)門(men)關(guan)閉。

特點：在真空、負壓(ya)、零壓(ya)時能正(zheng)常工作，但(dan)通徑(jing)一(yi)般不超(chao)過25mm。

分步直(zhi)動式電磁閥(fa)

原理：它(ta)是一種直動(dong)和先導式(shi)相結合的原理，當(dang)入口與出(chu)(chu)口沒有壓差(cha)時(shi)(shi)，通(tong)電(dian)(dian)后(hou)，電(dian)(dian)磁力(li)(li)直接(jie)把(ba)先導小(xiao)閥和主(zhu)(zhu)閥關閉件依次向上提起(qi)，閥門打開。當(dang)入口與出(chu)(chu)口達到啟(qi)動(dong)壓差(cha)時(shi)(shi)，通(tong)電(dian)(dian)后(hou)，電(dian)(dian)磁力(li)(li)先導小(xiao)閥，主(zhu)(zhu)閥下(xia)腔(qiang)壓力(li)(li)上升(sheng)，上腔(qiang)壓力(li)(li)下(xia)降，從(cong)而(er)利用(yong)壓差(cha)把(ba)主(zhu)(zhu)閥向上推開；斷電(dian)(dian)時(shi)(shi)，先導閥利用(yong)彈簧(huang)力(li)(li)或介質壓力(li)(li)推動(dong)關閉件，向下(xia)移動(dong)，使閥門關閉。

特點：在零(ling)壓差或(huo)真空(kong)、高壓時亦能可*動作，但功率較大，要求必須(xu)水平安裝。

先導式(shi)電磁閥

原理：通(tong)(tong)電(dian)時，電(dian)磁力(li)(li)把先導(dao)(dao)孔(kong)打開，上(shang)(shang)腔(qiang)室壓(ya)(ya)力(li)(li)迅(xun)速下(xia)(xia)降，在(zai)關(guan) 閉件(jian)周圍形成上(shang)(shang)低下(xia)(xia)高(gao)的壓(ya)(ya)差(cha)，流體(ti)壓(ya)(ya)力(li)(li)推動(dong)關(guan)閉件(jian)向(xiang)上(shang)(shang)移(yi)(yi)動(dong)，閥(fa)門(men)打開；斷電(dian)時，彈簧力(li)(li)把先導(dao)(dao)孔(kong)關(guan)閉，入(ru)口壓(ya)(ya)力(li)(li)通(tong)(tong)過旁(pang)通(tong)(tong)孔(kong)迅(xun)速腔(qiang)室在(zai)關(guan)閥(fa)件(jian)周圍形成下(xia)(xia)低上(shang)(shang)高(gao)的壓(ya)(ya)差(cha)，流體(ti)壓(ya)(ya)力(li)(li)推動(dong)關(guan)閉件(jian)向(xiang)下(xia)(xia)移(yi)(yi)動(dong)，關(guan)閉閥(fa)門(men)。

特點：流(liu)體(ti)壓力(li)范圍上限較高，可任意(yi)安裝（需定制(zhi)）但必須滿足流(liu)體(ti)壓差條件。

2、電磁閥(fa)從閥(fa)結(jie)構和材料上(shang)的不同與原理上(shang)的區別，分(fen)(fen)為六個(ge)分(fen)(fen)支(zhi)小類(lei)：直(zhi)動(dong)膜片(pian)結(jie)構、分(fen)(fen)步直(zhi)動(dong)膜片(pian)結(jie)構、先導膜片(pian)結(jie)構、直(zhi)動(dong)活塞(sai)結(jie)構、分(fen)(fen)步直(zhi)動(dong)活塞(sai)結(jie)構、先導活塞(sai)結(jie)構。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)按照功能分類：水(shui)用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、油(you)用電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)等。