電(dian)磁(ci)(ci)閥(fa)（Electromagnetic valve）是(shi)用(yong)電(dian)磁(ci)(ci)控(kong)(kong)制(zhi)(zhi)的(de)工業設備，是(shi)用(yong)來控(kong)(kong)制(zhi)(zhi)流(liu)體的(de)自動化基礎元件(jian)，屬于(yu)執(zhi)行器(qi)，并不(bu)(bu)限于(yu)液(ye)壓、氣動。用(yong)在工業控(kong)(kong)制(zhi)(zhi)系統(tong)中調整介質的(de)方(fang)向、流(liu)量、速度(du)和(he)其(qi)他的(de)參數。電(dian)磁(ci)(ci)閥(fa)可以(yi)配合不(bu)(bu)同(tong)的(de)電(dian)路(lu)來實現(xian)預期的(de)控(kong)(kong)制(zhi)(zhi)，而(er)控(kong)(kong)制(zhi)(zhi)的(de)精度(du)和(he)靈活(huo)性都能(neng)夠保證(zheng)。電(dian)磁(ci)(ci)閥(fa)有很多種，不(bu)(bu)同(tong)的(de)電(dian)磁(ci)(ci)閥(fa)在控(kong)(kong)制(zhi)(zhi)系統(tong)的(de)不(bu)(bu)同(tong)位置發揮作(zuo)用(yong)，最常用(yong)的(de)是(shi)單向閥(fa)、安全閥(fa)、方(fang)向控(kong)(kong)制(zhi)(zhi)閥(fa)、速度(du)調節閥(fa)等。

電磁閥里有(you)密閉(bi)的腔，在不同(tong)位置(zhi)開(kai)有(you)通孔(kong)，每個孔(kong)連接不同(tong)的油(you)(you)管(guan)(guan)，腔中間是活(huo)(huo)塞(sai)，兩面是兩塊電磁鐵，哪面的磁鐵線圈通電閥體就(jiu)會(hui)被吸引到哪邊，通過控制(zhi)閥體的移動來開(kai)啟或關(guan)閉(bi)不同(tong)的排油(you)(you)孔(kong)，而進油(you)(you)孔(kong)是常(chang)開(kai)的，液壓油(you)(you)就(jiu)會(hui)進入(ru)不同(tong)的排油(you)(you)管(guan)(guan)，然后通過油(you)(you)的壓力來推動油(you)(you)缸的活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又(you)帶動活(huo)(huo)塞(sai)桿(gan)，活(huo)(huo)塞(sai)桿(gan)帶動機械(xie)裝置(zhi)。這樣通過控制(zhi)電磁鐵的電流(liu)通斷就(jiu)控制(zhi)了機械(xie)運(yun)動。

1、電磁閥從原理上(shang)分(fen)為(wei)三大類：

直(zhi)動式電磁閥

原理：通電(dian)時(shi)，電(dian)磁線圈產生(sheng)電(dian)磁力(li)把關閉(bi)(bi)(bi)件(jian)從(cong)閥座(zuo)上提起，閥門(men)打開；斷電(dian)時(shi)，電(dian)磁力(li)消(xiao)失，彈簧(huang)把關閉(bi)(bi)(bi)件(jian)壓在閥座(zuo)上，閥門(men)關閉(bi)(bi)(bi)。

特點：在真空、負(fu)壓、零壓時能正常工(gong)作(zuo)，但通徑一(yi)般(ban)不(bu)超過(guo)25mm。

分步直動式電磁(ci)閥

原(yuan)理：它(ta)是一(yi)種直動(dong)和(he)先(xian)導(dao)(dao)式相(xiang)結合(he)的原(yuan)理，當入(ru)口與出(chu)口沒有壓差(cha)時，通(tong)電(dian)后，電(dian)磁(ci)力(li)直接把(ba)先(xian)導(dao)(dao)小閥和(he)主(zhu)(zhu)(zhu)閥關(guan)閉件依次向(xiang)上(shang)提(ti)起，閥門(men)(men)打(da)開。當入(ru)口與出(chu)口達到啟動(dong)壓差(cha)時，通(tong)電(dian)后，電(dian)磁(ci)力(li)先(xian)導(dao)(dao)小閥，主(zhu)(zhu)(zhu)閥下腔壓力(li)上(shang)升(sheng)，上(shang)腔壓力(li)下降，從而利用(yong)壓差(cha)把(ba)主(zhu)(zhu)(zhu)閥向(xiang)上(shang)推(tui)開；斷電(dian)時，先(xian)導(dao)(dao)閥利用(yong)彈簧(huang)力(li)或介質壓力(li)推(tui)動(dong)關(guan)閉件，向(xiang)下移動(dong)，使閥門(men)(men)關(guan)閉。

特點：在零壓(ya)差(cha)或真空(kong)、高壓(ya)時亦(yi)能可*動(dong)作，但功(gong)率較大(da)，要(yao)求(qiu)必(bi)須(xu)水(shui)平(ping)安裝。

先導(dao)式電(dian)磁閥

原理：通(tong)電時(shi)，電磁力把先導孔打開，上(shang)(shang)腔室壓(ya)力迅速下(xia)降(jiang)，在關(guan)(guan)(guan) 閉(bi)件周圍(wei)(wei)形成上(shang)(shang)低下(xia)高的壓(ya)差(cha)，流體(ti)壓(ya)力推動(dong)(dong)關(guan)(guan)(guan)閉(bi)件向上(shang)(shang)移(yi)(yi)動(dong)(dong)，閥門(men)打開；斷電時(shi)，彈簧(huang)力把先導孔關(guan)(guan)(guan)閉(bi)，入口壓(ya)力通(tong)過(guo)旁(pang)通(tong)孔迅速腔室在關(guan)(guan)(guan)閥件周圍(wei)(wei)形成下(xia)低上(shang)(shang)高的壓(ya)差(cha)，流體(ti)壓(ya)力推動(dong)(dong)關(guan)(guan)(guan)閉(bi)件向下(xia)移(yi)(yi)動(dong)(dong)，關(guan)(guan)(guan)閉(bi)閥門(men)。

特點：流(liu)體壓(ya)力(li)范圍上限較高(gao)，可任意安裝（需定制）但必須(xu)滿足流(liu)體壓(ya)差條(tiao)件(jian)。

2、電磁閥從(cong)閥結構(gou)和材料上的(de)不同與原理上的(de)區別，分(fen)(fen)為六個分(fen)(fen)支小類：直動膜片(pian)結構(gou)、分(fen)(fen)步直動膜片(pian)結構(gou)、先(xian)導膜片(pian)結構(gou)、直動活(huo)(huo)塞結構(gou)、分(fen)(fen)步直動活(huo)(huo)塞結構(gou)、先(xian)導活(huo)(huo)塞結構(gou)。

3、電(dian)(dian)(dian)磁(ci)(ci)閥(fa)按照功(gong)能分類：水用電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、蒸(zheng)汽(qi)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、制冷電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、低溫電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、燃氣電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、消防(fang)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氨用電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、氣體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、微型(xing)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、脈沖電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、液壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa) 常(chang)開電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、油(you)用電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、直(zhi)流電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、高壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)、防(fang)爆電(dian)(dian)(dian)磁(ci)(ci)閥(fa)等。