電(dian)磁閥(fa)(fa)（Electromagnetic valve）是用電(dian)磁控(kong)(kong)(kong)制的(de)(de)(de)工業設(she)備，是用來控(kong)(kong)(kong)制流體的(de)(de)(de)自動化基礎元件(jian)，屬于(yu)(yu)執行器，并不限(xian)于(yu)(yu)液壓(ya)、氣動。用在(zai)工業控(kong)(kong)(kong)制系(xi)統(tong)中調(diao)整介(jie)質的(de)(de)(de)方(fang)向(xiang)、流量、速度和其他的(de)(de)(de)參數。電(dian)磁閥(fa)(fa)可以配合不同(tong)(tong)的(de)(de)(de)電(dian)路來實現預期的(de)(de)(de)控(kong)(kong)(kong)制，而控(kong)(kong)(kong)制的(de)(de)(de)精度和靈活性(xing)都能夠保證。電(dian)磁閥(fa)(fa)有很多種，不同(tong)(tong)的(de)(de)(de)電(dian)磁閥(fa)(fa)在(zai)控(kong)(kong)(kong)制系(xi)統(tong)的(de)(de)(de)不同(tong)(tong)位置發揮作用，最常用的(de)(de)(de)是單向(xiang)閥(fa)(fa)、安(an)全閥(fa)(fa)、方(fang)向(xiang)控(kong)(kong)(kong)制閥(fa)(fa)、速度調(diao)節(jie)閥(fa)(fa)等。

電(dian)(dian)(dian)(dian)磁閥里有密閉(bi)的(de)(de)(de)腔，在不(bu)(bu)同位置開有通(tong)(tong)孔(kong)，每個孔(kong)連接不(bu)(bu)同的(de)(de)(de)油(you)管(guan)，腔中(zhong)間(jian)是活塞(sai)(sai)(sai)，兩面是兩塊電(dian)(dian)(dian)(dian)磁鐵，哪面的(de)(de)(de)磁鐵線圈(quan)通(tong)(tong)電(dian)(dian)(dian)(dian)閥體就(jiu)(jiu)會被吸引到哪邊，通(tong)(tong)過控(kong)制(zhi)閥體的(de)(de)(de)移動(dong)(dong)來(lai)開啟或(huo)關(guan)閉(bi)不(bu)(bu)同的(de)(de)(de)排油(you)孔(kong)，而進油(you)孔(kong)是常開的(de)(de)(de)，液壓(ya)油(you)就(jiu)(jiu)會進入不(bu)(bu)同的(de)(de)(de)排油(you)管(guan)，然后通(tong)(tong)過油(you)的(de)(de)(de)壓(ya)力(li)來(lai)推動(dong)(dong)油(you)缸的(de)(de)(de)活塞(sai)(sai)(sai)，活塞(sai)(sai)(sai)又帶(dai)動(dong)(dong)活塞(sai)(sai)(sai)桿(gan)，活塞(sai)(sai)(sai)桿(gan)帶(dai)動(dong)(dong)機械裝置。這樣通(tong)(tong)過控(kong)制(zhi)電(dian)(dian)(dian)(dian)磁鐵的(de)(de)(de)電(dian)(dian)(dian)(dian)流通(tong)(tong)斷就(jiu)(jiu)控(kong)制(zhi)了機械運動(dong)(dong)。

1、電(dian)磁閥從原理(li)上分為三大類：

直(zhi)動(dong)式電磁(ci)閥(fa)

原(yuan)理：通電(dian)時，電(dian)磁(ci)(ci)線圈產(chan)生(sheng)電(dian)磁(ci)(ci)力把(ba)關閉(bi)件從閥(fa)座上提起，閥(fa)門打開；斷電(dian)時，電(dian)磁(ci)(ci)力消失，彈簧把(ba)關閉(bi)件壓在閥(fa)座上，閥(fa)門關閉(bi)。

特(te)點：在真空、負壓、零(ling)壓時能(neng)正常工(gong)作，但通(tong)徑(jing)一般不(bu)超過25mm。

分步直動式電磁閥

原(yuan)理：它是一種(zhong)直(zhi)動(dong)(dong)和先導(dao)式相結(jie)合的(de)原(yuan)理，當(dang)入口(kou)與出(chu)口(kou)沒有壓差(cha)時(shi)，通電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)(li)直(zhi)接把先導(dao)小閥(fa)(fa)(fa)和主(zhu)閥(fa)(fa)(fa)關(guan)閉(bi)件(jian)依次向(xiang)上(shang)提起(qi)，閥(fa)(fa)(fa)門(men)打開(kai)。當(dang)入口(kou)與出(chu)口(kou)達到啟(qi)動(dong)(dong)壓差(cha)時(shi)，通電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)(li)先導(dao)小閥(fa)(fa)(fa)，主(zhu)閥(fa)(fa)(fa)下腔(qiang)壓力(li)(li)上(shang)升，上(shang)腔(qiang)壓力(li)(li)下降，從而利(li)用(yong)壓差(cha)把主(zhu)閥(fa)(fa)(fa)向(xiang)上(shang)推開(kai)；斷電(dian)(dian)時(shi)，先導(dao)閥(fa)(fa)(fa)利(li)用(yong)彈簧(huang)力(li)(li)或介質壓力(li)(li)推動(dong)(dong)關(guan)閉(bi)件(jian)，向(xiang)下移動(dong)(dong)，使閥(fa)(fa)(fa)門(men)關(guan)閉(bi)。

特(te)點：在零壓差或真空、高壓時亦能(neng)可(ke)*動作，但功率較大，要求必須(xu)水(shui)平安裝。

先導式電(dian)磁閥

原(yuan)理：通電時，電磁力(li)把先(xian)導(dao)孔打(da)開，上(shang)(shang)(shang)腔室(shi)壓(ya)(ya)(ya)(ya)(ya)力(li)迅速下降，在關(guan) 閉(bi)件周(zhou)圍形成上(shang)(shang)(shang)低下高(gao)的(de)壓(ya)(ya)(ya)(ya)(ya)差(cha)，流(liu)體壓(ya)(ya)(ya)(ya)(ya)力(li)推動(dong)(dong)關(guan)閉(bi)件向上(shang)(shang)(shang)移動(dong)(dong)，閥門打(da)開；斷電時，彈簧力(li)把先(xian)導(dao)孔關(guan)閉(bi)，入(ru)口壓(ya)(ya)(ya)(ya)(ya)力(li)通過旁通孔迅速腔室(shi)在關(guan)閥件周(zhou)圍形成下低上(shang)(shang)(shang)高(gao)的(de)壓(ya)(ya)(ya)(ya)(ya)差(cha)，流(liu)體壓(ya)(ya)(ya)(ya)(ya)力(li)推動(dong)(dong)關(guan)閉(bi)件向下移動(dong)(dong)，關(guan)閉(bi)閥門。

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

2、電磁閥從閥結(jie)構和材料(liao)上的不同與原理上的區別，分為六個分支小類(lei)：直動膜(mo)片結(jie)構、分步(bu)直動膜(mo)片結(jie)構、先導(dao)(dao)膜(mo)片結(jie)構、直動活(huo)塞結(jie)構、分步(bu)直動活(huo)塞結(jie)構、先導(dao)(dao)活(huo)塞結(jie)構。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按照功能分類：水用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃(ran)氣電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨(an)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油(you)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等。