電(dian)(dian)(dian)(dian)(dian)磁閥（Electromagnetic valve）是用電(dian)(dian)(dian)(dian)(dian)磁控(kong)制(zhi)(zhi)的(de)(de)(de)(de)工(gong)業(ye)(ye)設備，是用來控(kong)制(zhi)(zhi)流體的(de)(de)(de)(de)自(zi)動(dong)化基礎元(yuan)件(jian)，屬于執行器(qi)，并不(bu)(bu)限于液壓、氣動(dong)。用在(zai)工(gong)業(ye)(ye)控(kong)制(zhi)(zhi)系統中調(diao)整介質(zhi)的(de)(de)(de)(de)方(fang)(fang)向、流量、速(su)度和其他的(de)(de)(de)(de)參數。電(dian)(dian)(dian)(dian)(dian)磁閥可以配合不(bu)(bu)同的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)路(lu)來實現預(yu)期的(de)(de)(de)(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)(de)(de)(de)精度和靈活性都能夠(gou)保(bao)證。電(dian)(dian)(dian)(dian)(dian)磁閥有很多種，不(bu)(bu)同的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁閥在(zai)控(kong)制(zhi)(zhi)系統的(de)(de)(de)(de)不(bu)(bu)同位(wei)置發揮作用，最常用的(de)(de)(de)(de)是單向閥、安全閥、方(fang)(fang)向控(kong)制(zhi)(zhi)閥、速(su)度調(diao)節閥等。

電磁(ci)閥(fa)(fa)里有(you)密閉的(de)(de)(de)(de)腔，在(zai)不(bu)同位(wei)置開有(you)通(tong)孔(kong)(kong)，每個孔(kong)(kong)連接不(bu)同的(de)(de)(de)(de)油(you)管，腔中間是(shi)活(huo)塞，兩(liang)面(mian)是(shi)兩(liang)塊(kuai)電磁(ci)鐵，哪(na)面(mian)的(de)(de)(de)(de)磁(ci)鐵線圈通(tong)電閥(fa)(fa)體就(jiu)會(hui)被吸引到哪(na)邊，通(tong)過控制閥(fa)(fa)體的(de)(de)(de)(de)移動(dong)(dong)來開啟或(huo)關閉不(bu)同的(de)(de)(de)(de)排油(you)孔(kong)(kong)，而進油(you)孔(kong)(kong)是(shi)常開的(de)(de)(de)(de)，液壓油(you)就(jiu)會(hui)進入不(bu)同的(de)(de)(de)(de)排油(you)管，然后通(tong)過油(you)的(de)(de)(de)(de)壓力(li)來推動(dong)(dong)油(you)缸的(de)(de)(de)(de)活(huo)塞，活(huo)塞又帶(dai)動(dong)(dong)活(huo)塞桿(gan)，活(huo)塞桿(gan)帶(dai)動(dong)(dong)機械裝置。這樣通(tong)過控制電磁(ci)鐵的(de)(de)(de)(de)電流通(tong)斷就(jiu)控制了機械運動(dong)(dong)。

1、電磁(ci)閥從原理上分(fen)為三大類：

直動(dong)式電磁閥(fa)

原(yuan)理(li)：通電(dian)時，電(dian)磁線圈產生電(dian)磁力把關(guan)閉件從閥座上(shang)提起，閥門打(da)開；斷電(dian)時，電(dian)磁力消(xiao)失，彈(dan)簧把關(guan)閉件壓在閥座上(shang)，閥門關(guan)閉。

特點：在真空、負壓、零壓時能正常工作，但通(tong)徑一般(ban)不超過25mm。

分步直動式(shi)電磁閥(fa)

原理：它是一種直動(dong)(dong)(dong)和(he)先(xian)(xian)導式相(xiang)結合的(de)原理，當(dang)入口與出口沒有壓差時(shi)，通電后(hou)，電磁力(li)直接(jie)把先(xian)(xian)導小閥(fa)(fa)和(he)主(zhu)閥(fa)(fa)關閉(bi)件依次向上提起(qi)，閥(fa)(fa)門打開(kai)。當(dang)入口與出口達到啟動(dong)(dong)(dong)壓差時(shi)，通電后(hou)，電磁力(li)先(xian)(xian)導小閥(fa)(fa)，主(zhu)閥(fa)(fa)下腔壓力(li)上升，上腔壓力(li)下降(jiang)，從而(er)利(li)用(yong)壓差把主(zhu)閥(fa)(fa)向上推開(kai)；斷電時(shi)，先(xian)(xian)導閥(fa)(fa)利(li)用(yong)彈簧(huang)力(li)或(huo)介質壓力(li)推動(dong)(dong)(dong)關閉(bi)件，向下移動(dong)(dong)(dong)，使閥(fa)(fa)門關閉(bi)。

特點：在零壓差或(huo)真空、高壓時亦能可*動作，但功率較大，要求必須水平安裝。

先導式(shi)電磁閥

原理：通電(dian)時(shi)，電(dian)磁力(li)把先(xian)導(dao)孔(kong)打開，上腔室壓(ya)(ya)(ya)力(li)迅(xun)速下降，在(zai)關 閉(bi)件周圍形(xing)(xing)成上低下高(gao)的壓(ya)(ya)(ya)差，流(liu)體壓(ya)(ya)(ya)力(li)推動(dong)關閉(bi)件向(xiang)上移動(dong)，閥(fa)門打開；斷電(dian)時(shi)，彈簧力(li)把先(xian)導(dao)孔(kong)關閉(bi)，入口(kou)壓(ya)(ya)(ya)力(li)通過旁通孔(kong)迅(xun)速腔室在(zai)關閥(fa)件周圍形(xing)(xing)成下低上高(gao)的壓(ya)(ya)(ya)差，流(liu)體壓(ya)(ya)(ya)力(li)推動(dong)關閉(bi)件向(xiang)下移動(dong)，關閉(bi)閥(fa)門。

特點：流(liu)體壓力(li)范圍上(shang)限較高(gao)，可任意(yi)安(an)裝（需定制）但必須滿足流(liu)體壓差條件。

2、電磁閥(fa)從閥(fa)結(jie)(jie)構(gou)(gou)和材料(liao)上的(de)不同與原理上的(de)區別，分為六(liu)個分支(zhi)小類：直(zhi)(zhi)(zhi)動(dong)膜(mo)片結(jie)(jie)構(gou)(gou)、分步(bu)(bu)直(zhi)(zhi)(zhi)動(dong)膜(mo)片結(jie)(jie)構(gou)(gou)、先導(dao)膜(mo)片結(jie)(jie)構(gou)(gou)、直(zhi)(zhi)(zhi)動(dong)活(huo)塞(sai)結(jie)(jie)構(gou)(gou)、分步(bu)(bu)直(zhi)(zhi)(zhi)動(dong)活(huo)塞(sai)結(jie)(jie)構(gou)(gou)、先導(dao)活(huo)塞(sai)結(jie)(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)按照功能分類：水用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氨(an)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆(bao)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)(fa)等(deng)。