電(dian)(dian)(dian)磁閥(fa)(fa)(fa)(fa)（Electromagnetic valve）是用(yong)(yong)(yong)電(dian)(dian)(dian)磁控(kong)(kong)制的(de)(de)工業(ye)設(she)備，是用(yong)(yong)(yong)來控(kong)(kong)制流體的(de)(de)自動(dong)化基礎元(yuan)件，屬于(yu)執行器(qi)，并不(bu)(bu)限于(yu)液壓、氣動(dong)。用(yong)(yong)(yong)在工業(ye)控(kong)(kong)制系(xi)統中調整(zheng)介質(zhi)的(de)(de)方向、流量、速度和(he)其他的(de)(de)參數。電(dian)(dian)(dian)磁閥(fa)(fa)(fa)(fa)可以配(pei)合不(bu)(bu)同(tong)的(de)(de)電(dian)(dian)(dian)路來實(shi)現預期的(de)(de)控(kong)(kong)制，而(er)控(kong)(kong)制的(de)(de)精度和(he)靈(ling)活性都(dou)能夠保證。電(dian)(dian)(dian)磁閥(fa)(fa)(fa)(fa)有很多種，不(bu)(bu)同(tong)的(de)(de)電(dian)(dian)(dian)磁閥(fa)(fa)(fa)(fa)在控(kong)(kong)制系(xi)統的(de)(de)不(bu)(bu)同(tong)位置發揮作用(yong)(yong)(yong)，最常用(yong)(yong)(yong)的(de)(de)是單向閥(fa)(fa)(fa)(fa)、安全(quan)閥(fa)(fa)(fa)(fa)、方向控(kong)(kong)制閥(fa)(fa)(fa)(fa)、速度調節(jie)閥(fa)(fa)(fa)(fa)等。

電磁閥(fa)里(li)有密(mi)閉的(de)(de)腔，在(zai)不(bu)同位置開有通(tong)(tong)(tong)孔，每個孔連接不(bu)同的(de)(de)油(you)(you)(you)管，腔中間是(shi)活(huo)塞(sai)(sai)(sai)，兩面(mian)是(shi)兩塊電磁鐵，哪(na)面(mian)的(de)(de)磁鐵線圈通(tong)(tong)(tong)電閥(fa)體(ti)就(jiu)會被吸(xi)引到哪(na)邊，通(tong)(tong)(tong)過(guo)控(kong)制(zhi)閥(fa)體(ti)的(de)(de)移(yi)動(dong)來(lai)開啟或關閉不(bu)同的(de)(de)排油(you)(you)(you)孔，而(er)進油(you)(you)(you)孔是(shi)常開的(de)(de)，液壓(ya)油(you)(you)(you)就(jiu)會進入不(bu)同的(de)(de)排油(you)(you)(you)管，然后(hou)通(tong)(tong)(tong)過(guo)油(you)(you)(you)的(de)(de)壓(ya)力來(lai)推動(dong)油(you)(you)(you)缸(gang)的(de)(de)活(huo)塞(sai)(sai)(sai)，活(huo)塞(sai)(sai)(sai)又帶動(dong)活(huo)塞(sai)(sai)(sai)桿，活(huo)塞(sai)(sai)(sai)桿帶動(dong)機械(xie)裝置。這(zhe)樣(yang)通(tong)(tong)(tong)過(guo)控(kong)制(zhi)電磁鐵的(de)(de)電流(liu)通(tong)(tong)(tong)斷就(jiu)控(kong)制(zhi)了機械(xie)運動(dong)。

1、電磁閥從原理上分為三(san)大類：

直動式電磁閥

原理(li)：通電(dian)(dian)時(shi)，電(dian)(dian)磁(ci)線圈產生電(dian)(dian)磁(ci)力(li)把(ba)關閉(bi)件從閥座上提起，閥門(men)打開；斷電(dian)(dian)時(shi)，電(dian)(dian)磁(ci)力(li)消失，彈簧把(ba)關閉(bi)件壓在閥座上，閥門(men)關閉(bi)。

特點：在真空(kong)、負(fu)壓(ya)、零壓(ya)時能正(zheng)常工作，但通徑一般(ban)不(bu)超過25mm。

分步直(zhi)動式(shi)電磁閥

原(yuan)理：它(ta)是一(yi)種(zhong)直動(dong)(dong)和(he)先導(dao)(dao)式相(xiang)結(jie)合的原(yuan)理，當入(ru)口與出口沒有壓差(cha)時(shi)，通電(dian)后，電(dian)磁力直接把(ba)先導(dao)(dao)小閥(fa)和(he)主閥(fa)關閉(bi)件依(yi)次向上提起(qi)，閥(fa)門打(da)開。當入(ru)口與出口達到啟動(dong)(dong)壓差(cha)時(shi)，通電(dian)后，電(dian)磁力先導(dao)(dao)小閥(fa)，主閥(fa)下腔壓力上升，上腔壓力下降，從而利(li)用(yong)壓差(cha)把(ba)主閥(fa)向上推開；斷(duan)電(dian)時(shi)，先導(dao)(dao)閥(fa)利(li)用(yong)彈簧力或(huo)介質壓力推動(dong)(dong)關閉(bi)件，向下移動(dong)(dong)，使(shi)閥(fa)門關閉(bi)。

特點：在零壓差或真(zhen)空(kong)、高(gao)壓時(shi)亦能(neng)可*動(dong)作，但功率(lv)較大，要求必須(xu)水平安裝。

先導式(shi)電磁閥

原理(li)：通(tong)電(dian)時(shi)，電(dian)磁力(li)把先導孔打(da)開，上腔(qiang)室壓力(li)迅速(su)下(xia)(xia)降，在(zai)關(guan) 閉(bi)件周圍(wei)形(xing)成(cheng)上低(di)(di)下(xia)(xia)高的壓差(cha)，流體(ti)壓力(li)推動關(guan)閉(bi)件向上移動，閥(fa)門(men)打(da)開；斷電(dian)時(shi)，彈簧力(li)把先導孔關(guan)閉(bi)，入(ru)口壓力(li)通(tong)過(guo)旁(pang)通(tong)孔迅速(su)腔(qiang)室在(zai)關(guan)閥(fa)件周圍(wei)形(xing)成(cheng)下(xia)(xia)低(di)(di)上高的壓差(cha)，流體(ti)壓力(li)推動關(guan)閉(bi)件向下(xia)(xia)移動，關(guan)閉(bi)閥(fa)門(men)。

特點：流(liu)體壓力范圍上限較高(gao)，可任意安裝（需定制）但必須滿足流(liu)體壓差條件。

2、電(dian)磁閥從閥結(jie)(jie)構和(he)材料上(shang)的(de)(de)不同(tong)與原理上(shang)的(de)(de)區別，分(fen)為六個分(fen)支小類：直動(dong)膜片結(jie)(jie)構、分(fen)步(bu)直動(dong)膜片結(jie)(jie)構、先導膜片結(jie)(jie)構、直動(dong)活塞(sai)結(jie)(jie)構、分(fen)步(bu)直動(dong)活塞(sai)結(jie)(jie)構、先導活塞(sai)結(jie)(jie)構。

3、電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥按照功能分類(lei)：水(shui)用(yong)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、蒸汽電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、制冷電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、低溫(wen)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、燃氣電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、消(xiao)防電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、氨用(yong)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、氣體(ti)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、液體(ti)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、微型電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、脈(mo)沖(chong)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、液壓電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥 常開電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、油用(yong)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、直流(liu)電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、高(gao)壓電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥、防爆電(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥等(deng)。