電(dian)磁(ci)閥(fa)（Electromagnetic valve）是(shi)用電(dian)磁(ci)控(kong)(kong)制(zhi)(zhi)(zhi)的(de)工業(ye)(ye)設備，是(shi)用來控(kong)(kong)制(zhi)(zhi)(zhi)流體的(de)自動化基礎元件，屬(shu)于(yu)執(zhi)行器，并不限于(yu)液(ye)壓(ya)、氣動。用在(zai)(zai)工業(ye)(ye)控(kong)(kong)制(zhi)(zhi)(zhi)系統中調整介(jie)質的(de)方(fang)向、流量、速度(du)和其(qi)他的(de)參數。電(dian)磁(ci)閥(fa)可以配(pei)合不同(tong)的(de)電(dian)路來實現(xian)預期的(de)控(kong)(kong)制(zhi)(zhi)(zhi)，而(er)控(kong)(kong)制(zhi)(zhi)(zhi)的(de)精(jing)度(du)和靈活(huo)性(xing)都能夠(gou)保證。電(dian)磁(ci)閥(fa)有很多種(zhong)，不同(tong)的(de)電(dian)磁(ci)閥(fa)在(zai)(zai)控(kong)(kong)制(zhi)(zhi)(zhi)系統的(de)不同(tong)位置發揮(hui)作用，最常用的(de)是(shi)單向閥(fa)、安全閥(fa)、方(fang)向控(kong)(kong)制(zhi)(zhi)(zhi)閥(fa)、速度(du)調節閥(fa)等。

電磁(ci)閥里有密閉(bi)(bi)的腔，在不(bu)同(tong)位置開有通(tong)(tong)孔(kong)，每個孔(kong)連接不(bu)同(tong)的油(you)管，腔中(zhong)間是活塞(sai)，兩面是兩塊電磁(ci)鐵，哪面的磁(ci)鐵線圈通(tong)(tong)電閥體就(jiu)會被吸引到哪邊，通(tong)(tong)過控制(zhi)閥體的移(yi)動(dong)來(lai)開啟(qi)或關(guan)閉(bi)(bi)不(bu)同(tong)的排油(you)孔(kong)，而進油(you)孔(kong)是常開的，液壓油(you)就(jiu)會進入不(bu)同(tong)的排油(you)管，然后通(tong)(tong)過油(you)的壓力來(lai)推動(dong)油(you)缸的活塞(sai)，活塞(sai)又帶動(dong)活塞(sai)桿(gan)，活塞(sai)桿(gan)帶動(dong)機械(xie)裝置。這樣通(tong)(tong)過控制(zhi)電磁(ci)鐵的電流通(tong)(tong)斷就(jiu)控制(zhi)了機械(xie)運動(dong)。

1、電磁(ci)閥從(cong)原(yuan)理上分為三大類：

直動式電磁閥

原理：通電(dian)時(shi)，電(dian)磁線(xian)圈產生電(dian)磁力(li)把關閉(bi)件(jian)從閥(fa)座上提起(qi)，閥(fa)門(men)打開；斷電(dian)時(shi)，電(dian)磁力(li)消失，彈簧(huang)把關閉(bi)件(jian)壓在閥(fa)座上，閥(fa)門(men)關閉(bi)。

特點(dian)：在真(zhen)空(kong)、負壓、零壓時能正常工作，但(dan)通徑一般不超過25mm。

分步直動式(shi)電(dian)磁閥(fa)

原(yuan)理：它是一種(zhong)直動和(he)先(xian)(xian)導(dao)(dao)(dao)式相結合的原(yuan)理，當入口(kou)與出(chu)口(kou)沒有壓差時(shi)(shi)，通電(dian)(dian)后(hou)，電(dian)(dian)磁力直接(jie)把先(xian)(xian)導(dao)(dao)(dao)小(xiao)(xiao)閥和(he)主(zhu)閥關閉件(jian)依次向(xiang)上提起，閥門打開(kai)。當入口(kou)與出(chu)口(kou)達到啟動壓差時(shi)(shi)，通電(dian)(dian)后(hou)，電(dian)(dian)磁力先(xian)(xian)導(dao)(dao)(dao)小(xiao)(xiao)閥，主(zhu)閥下(xia)腔(qiang)壓力上升(sheng)，上腔(qiang)壓力下(xia)降，從而利用(yong)壓差把主(zhu)閥向(xiang)上推開(kai)；斷電(dian)(dian)時(shi)(shi)，先(xian)(xian)導(dao)(dao)(dao)閥利用(yong)彈(dan)簧(huang)力或介質壓力推動關閉件(jian)，向(xiang)下(xia)移動，使閥門關閉。

特點：在零壓差(cha)或真(zhen)空、高壓時亦能可*動(dong)作，但功率較(jiao)大，要求必須水平(ping)安裝。

先導式電磁閥

原理：通(tong)電時，電磁力(li)把先導(dao)孔(kong)打開，上(shang)(shang)腔室(shi)壓(ya)力(li)迅(xun)速下(xia)降(jiang)，在關(guan) 閉(bi)件(jian)周圍形成上(shang)(shang)低下(xia)高的壓(ya)差，流體壓(ya)力(li)推動關(guan)閉(bi)件(jian)向上(shang)(shang)移(yi)動，閥門打開；斷電時，彈簧力(li)把先導(dao)孔(kong)關(guan)閉(bi)，入口壓(ya)力(li)通(tong)過旁通(tong)孔(kong)迅(xun)速腔室(shi)在關(guan)閥件(jian)周圍形成下(xia)低上(shang)(shang)高的壓(ya)差，流體壓(ya)力(li)推動關(guan)閉(bi)件(jian)向下(xia)移(yi)動，關(guan)閉(bi)閥門。

特點：流體(ti)壓力范(fan)圍上(shang)限較(jiao)高，可任意安裝（需定制(zhi)）但必須(xu)滿(man)足流體(ti)壓差條件。

2、電磁閥(fa)從閥(fa)結(jie)(jie)構(gou)和(he)材料上(shang)的不同(tong)與原理上(shang)的區別，分(fen)為六個分(fen)支(zhi)小類：直(zhi)(zhi)動(dong)膜(mo)片(pian)(pian)結(jie)(jie)構(gou)、分(fen)步直(zhi)(zhi)動(dong)膜(mo)片(pian)(pian)結(jie)(jie)構(gou)、先導膜(mo)片(pian)(pian)結(jie)(jie)構(gou)、直(zhi)(zhi)動(dong)活(huo)塞結(jie)(jie)構(gou)、分(fen)步直(zhi)(zhi)動(dong)活(huo)塞結(jie)(jie)構(gou)、先導活(huo)塞結(jie)(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)按照功(gong)能分類(lei)：水用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、制冷(leng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、低(di)溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、燃(ran)氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、消防(fang)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa) 常(chang)開(kai)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、防(fang)爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)等。