電(dian)(dian)磁(ci)閥（Electromagnetic valve）是用(yong)電(dian)(dian)磁(ci)控(kong)制的(de)工(gong)業(ye)設(she)備，是用(yong)來(lai)控(kong)制流體(ti)的(de)自(zi)動化基礎元件，屬于(yu)執行(xing)器，并(bing)不(bu)限于(yu)液壓、氣動。用(yong)在(zai)工(gong)業(ye)控(kong)制系(xi)統中調(diao)(diao)整介質(zhi)的(de)方向(xiang)、流量(liang)、速(su)度和(he)其他(ta)的(de)參數。電(dian)(dian)磁(ci)閥可(ke)以配(pei)合(he)不(bu)同的(de)電(dian)(dian)路來(lai)實現預期的(de)控(kong)制，而控(kong)制的(de)精度和(he)靈活性(xing)都能(neng)夠保證。電(dian)(dian)磁(ci)閥有很(hen)多種，不(bu)同的(de)電(dian)(dian)磁(ci)閥在(zai)控(kong)制系(xi)統的(de)不(bu)同位(wei)置(zhi)發揮作用(yong)，最常用(yong)的(de)是單向(xiang)閥、安全(quan)閥、方向(xiang)控(kong)制閥、速(su)度調(diao)(diao)節閥等。

電(dian)(dian)(dian)磁閥里(li)有密閉的(de)(de)(de)腔，在不(bu)同(tong)位置開(kai)(kai)有通孔(kong)(kong)，每(mei)個孔(kong)(kong)連接不(bu)同(tong)的(de)(de)(de)油(you)(you)管(guan)，腔中間是(shi)活(huo)塞(sai)(sai)，兩(liang)面是(shi)兩(liang)塊電(dian)(dian)(dian)磁鐵，哪面的(de)(de)(de)磁鐵線(xian)圈通電(dian)(dian)(dian)閥體就會被吸引到哪邊，通過控(kong)(kong)制閥體的(de)(de)(de)移動(dong)來開(kai)(kai)啟或關閉不(bu)同(tong)的(de)(de)(de)排油(you)(you)孔(kong)(kong)，而進油(you)(you)孔(kong)(kong)是(shi)常開(kai)(kai)的(de)(de)(de)，液壓油(you)(you)就會進入不(bu)同(tong)的(de)(de)(de)排油(you)(you)管(guan)，然后通過油(you)(you)的(de)(de)(de)壓力來推(tui)動(dong)油(you)(you)缸的(de)(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又帶動(dong)活(huo)塞(sai)(sai)桿，活(huo)塞(sai)(sai)桿帶動(dong)機械(xie)裝(zhuang)置。這樣通過控(kong)(kong)制電(dian)(dian)(dian)磁鐵的(de)(de)(de)電(dian)(dian)(dian)流通斷就控(kong)(kong)制了機械(xie)運動(dong)。

1、電磁閥(fa)從(cong)原理上分為三大類：

直動式電磁(ci)閥(fa)

原理：通電(dian)(dian)時，電(dian)(dian)磁線圈(quan)產生電(dian)(dian)磁力把(ba)關閉(bi)件從閥座(zuo)上(shang)提起，閥門打開；斷(duan)電(dian)(dian)時，電(dian)(dian)磁力消失，彈簧把(ba)關閉(bi)件壓在閥座(zuo)上(shang)，閥門關閉(bi)。

特(te)點：在真空(kong)、負壓、零壓時能正常工(gong)作，但通徑一般不超過25mm。

分步直動(dong)式電磁閥

原(yuan)理(li)：它是(shi)一(yi)種直(zhi)動(dong)和先(xian)(xian)導式(shi)相結合的原(yuan)理(li)，當入(ru)口與出(chu)口沒有壓(ya)(ya)差時(shi)(shi)，通電(dian)后(hou)，電(dian)磁力直(zhi)接把(ba)先(xian)(xian)導小閥(fa)和主(zhu)閥(fa)關閉件依次向上提起(qi)，閥(fa)門(men)打開。當入(ru)口與出(chu)口達(da)到啟動(dong)壓(ya)(ya)差時(shi)(shi)，通電(dian)后(hou)，電(dian)磁力先(xian)(xian)導小閥(fa)，主(zhu)閥(fa)下腔壓(ya)(ya)力上升，上腔壓(ya)(ya)力下降，從而利用(yong)壓(ya)(ya)差把(ba)主(zhu)閥(fa)向上推(tui)開；斷(duan)電(dian)時(shi)(shi)，先(xian)(xian)導閥(fa)利用(yong)彈簧(huang)力或介質(zhi)壓(ya)(ya)力推(tui)動(dong)關閉件，向下移動(dong)，使閥(fa)門(men)關閉。

特點：在零壓(ya)差或真空、高(gao)壓(ya)時亦能(neng)可*動作，但功(gong)率較(jiao)大，要求必須水平安裝(zhuang)。

先導式電(dian)磁(ci)閥(fa)

原理：通(tong)電時，電磁力把先(xian)導孔打開，上腔室(shi)壓力迅速下降，在(zai)關(guan) 閉(bi)(bi)(bi)件周圍(wei)形(xing)成上低下高(gao)(gao)的(de)壓差，流體(ti)壓力推(tui)動(dong)關(guan)閉(bi)(bi)(bi)件向上移動(dong)，閥(fa)門打開；斷(duan)電時，彈(dan)簧(huang)力把先(xian)導孔關(guan)閉(bi)(bi)(bi)，入口壓力通(tong)過旁通(tong)孔迅速腔室(shi)在(zai)關(guan)閥(fa)件周圍(wei)形(xing)成下低上高(gao)(gao)的(de)壓差，流體(ti)壓力推(tui)動(dong)關(guan)閉(bi)(bi)(bi)件向下移動(dong)，關(guan)閉(bi)(bi)(bi)閥(fa)門。

特點：流(liu)體壓力(li)范圍(wei)上限較(jiao)高，可任意安裝（需定制(zhi)）但(dan)必須滿足流(liu)體壓差條件(jian)。

2、電(dian)磁閥(fa)從閥(fa)結(jie)(jie)(jie)構(gou)(gou)和材料上的不同(tong)與原理(li)上的區別，分為六個分支小類(lei)：直動(dong)(dong)膜片結(jie)(jie)(jie)構(gou)(gou)、分步直動(dong)(dong)膜片結(jie)(jie)(jie)構(gou)(gou)、先(xian)導(dao)膜片結(jie)(jie)(jie)構(gou)(gou)、直動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)(jie)構(gou)(gou)、分步直動(dong)(dong)活(huo)塞(sai)(sai)結(jie)(jie)(jie)構(gou)(gou)、先(xian)導(dao)活(huo)塞(sai)(sai)結(jie)(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)按照功能(neng)分類：水(shui)用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、蒸(zheng)汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、消防(fang)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氨(an)用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、脈(mo)沖(chong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)、防(fang)爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)等。