電(dian)(dian)磁閥(fa)(fa)（Electromagnetic valve）是(shi)(shi)用(yong)(yong)電(dian)(dian)磁控制(zhi)(zhi)(zhi)的(de)(de)工(gong)業設(she)備，是(shi)(shi)用(yong)(yong)來控制(zhi)(zhi)(zhi)流體的(de)(de)自(zi)動化基礎元件(jian)，屬于執行器(qi)，并不限(xian)于液壓(ya)、氣動。用(yong)(yong)在(zai)工(gong)業控制(zhi)(zhi)(zhi)系(xi)統中調整介質的(de)(de)方向(xiang)(xiang)、流量(liang)、速度和其他的(de)(de)參數(shu)。電(dian)(dian)磁閥(fa)(fa)可以配合不同的(de)(de)電(dian)(dian)路來實現預期的(de)(de)控制(zhi)(zhi)(zhi)，而控制(zhi)(zhi)(zhi)的(de)(de)精(jing)度和靈活性(xing)都能(neng)夠保證。電(dian)(dian)磁閥(fa)(fa)有很多種，不同的(de)(de)電(dian)(dian)磁閥(fa)(fa)在(zai)控制(zhi)(zhi)(zhi)系(xi)統的(de)(de)不同位置發揮作用(yong)(yong)，最常用(yong)(yong)的(de)(de)是(shi)(shi)單向(xiang)(xiang)閥(fa)(fa)、安(an)全(quan)閥(fa)(fa)、方向(xiang)(xiang)控制(zhi)(zhi)(zhi)閥(fa)(fa)、速度調節(jie)閥(fa)(fa)等。

電(dian)磁(ci)(ci)閥(fa)里有密(mi)閉(bi)的(de)(de)腔(qiang)，在不同(tong)位(wei)置開(kai)有通(tong)(tong)孔(kong)，每個孔(kong)連(lian)接不同(tong)的(de)(de)油(you)(you)(you)管(guan)，腔(qiang)中間是(shi)活(huo)塞(sai)(sai)，兩面是(shi)兩塊電(dian)磁(ci)(ci)鐵(tie)，哪(na)面的(de)(de)磁(ci)(ci)鐵(tie)線圈通(tong)(tong)電(dian)閥(fa)體就會(hui)被吸(xi)引到(dao)哪(na)邊，通(tong)(tong)過(guo)控(kong)制(zhi)閥(fa)體的(de)(de)移動來開(kai)啟或關閉(bi)不同(tong)的(de)(de)排油(you)(you)(you)孔(kong)，而進(jin)油(you)(you)(you)孔(kong)是(shi)常開(kai)的(de)(de)，液壓(ya)油(you)(you)(you)就會(hui)進(jin)入不同(tong)的(de)(de)排油(you)(you)(you)管(guan)，然后通(tong)(tong)過(guo)油(you)(you)(you)的(de)(de)壓(ya)力來推動油(you)(you)(you)缸的(de)(de)活(huo)塞(sai)(sai)，活(huo)塞(sai)(sai)又帶動活(huo)塞(sai)(sai)桿，活(huo)塞(sai)(sai)桿帶動機械(xie)裝置。這樣通(tong)(tong)過(guo)控(kong)制(zhi)電(dian)磁(ci)(ci)鐵(tie)的(de)(de)電(dian)流(liu)通(tong)(tong)斷就控(kong)制(zhi)了(le)機械(xie)運動。

1、電(dian)磁(ci)閥從原理(li)上分(fen)為三大類：

直動式(shi)電磁(ci)閥

原理：通電時，電磁(ci)線圈產(chan)生電磁(ci)力(li)把關閉件從閥(fa)(fa)座上(shang)提起，閥(fa)(fa)門(men)打(da)開；斷電時，電磁(ci)力(li)消失，彈(dan)簧把關閉件壓在閥(fa)(fa)座上(shang)，閥(fa)(fa)門(men)關閉。

特點(dian)：在真空、負(fu)壓(ya)、零壓(ya)時能正常工作，但通徑(jing)一般不超(chao)過25mm。

分步直動式電磁閥

原理(li)：它是一種直(zhi)動(dong)和(he)先導(dao)式相結合的(de)原理(li)，當入口與出(chu)口沒(mei)有壓(ya)差(cha)時，通電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)(li)直(zhi)接把先導(dao)小(xiao)閥(fa)和(he)主閥(fa)關(guan)閉件依次向(xiang)上(shang)提(ti)起，閥(fa)門打開(kai)。當入口與出(chu)口達到啟動(dong)壓(ya)差(cha)時，通電(dian)(dian)后，電(dian)(dian)磁(ci)力(li)(li)先導(dao)小(xiao)閥(fa)，主閥(fa)下腔(qiang)壓(ya)力(li)(li)上(shang)升，上(shang)腔(qiang)壓(ya)力(li)(li)下降，從而(er)利用壓(ya)差(cha)把主閥(fa)向(xiang)上(shang)推開(kai)；斷電(dian)(dian)時，先導(dao)閥(fa)利用彈簧(huang)力(li)(li)或介質壓(ya)力(li)(li)推動(dong)關(guan)閉件，向(xiang)下移動(dong)，使閥(fa)門關(guan)閉。

特點：在零壓差或真空、高壓時(shi)亦能可(ke)*動作，但(dan)功(gong)率較大，要(yao)求(qiu)必須水(shui)平安(an)裝。

先(xian)導式電磁閥

原理(li)：通(tong)電時(shi)，電磁力(li)(li)把先導(dao)孔打開(kai)，上(shang)(shang)(shang)腔室壓(ya)(ya)力(li)(li)迅(xun)速下(xia)(xia)降，在(zai)關(guan) 閉件(jian)(jian)周(zhou)圍形(xing)成上(shang)(shang)(shang)低下(xia)(xia)高(gao)的壓(ya)(ya)差(cha)，流體壓(ya)(ya)力(li)(li)推動(dong)(dong)(dong)關(guan)閉件(jian)(jian)向上(shang)(shang)(shang)移動(dong)(dong)(dong)，閥(fa)門打開(kai)；斷電時(shi)，彈簧力(li)(li)把先導(dao)孔關(guan)閉，入口壓(ya)(ya)力(li)(li)通(tong)過旁通(tong)孔迅(xun)速腔室在(zai)關(guan)閥(fa)件(jian)(jian)周(zhou)圍形(xing)成下(xia)(xia)低上(shang)(shang)(shang)高(gao)的壓(ya)(ya)差(cha)，流體壓(ya)(ya)力(li)(li)推動(dong)(dong)(dong)關(guan)閉件(jian)(jian)向下(xia)(xia)移動(dong)(dong)(dong)，關(guan)閉閥(fa)門。

特點：流體(ti)壓力范圍上(shang)限較高，可任意(yi)安裝（需定制）但(dan)必須滿足流體(ti)壓差條件。

2、電磁閥從閥結(jie)構和材料上(shang)的不同與原(yuan)理上(shang)的區別(bie)，分(fen)為六(liu)個分(fen)支小類：直(zhi)動膜片結(jie)構、分(fen)步直(zhi)動膜片結(jie)構、先(xian)導(dao)膜片結(jie)構、直(zhi)動活(huo)塞(sai)結(jie)構、分(fen)步直(zhi)動活(huo)塞(sai)結(jie)構、先(xian)導(dao)活(huo)塞(sai)結(jie)構。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)按照功能分類(lei)：水用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、低溫(wen)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、消防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、液體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、微(wei)(wei)型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、液壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、油用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)等。