電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是(shi)用(yong)電(dian)磁(ci)控(kong)制(zhi)的(de)(de)(de)工業設(she)備，是(shi)用(yong)來控(kong)制(zhi)流(liu)體的(de)(de)(de)自(zi)動化基礎(chu)元件，屬(shu)于執(zhi)行器(qi)，并不(bu)限(xian)于液壓、氣動。用(yong)在工業控(kong)制(zhi)系統中調整(zheng)介質的(de)(de)(de)方向(xiang)、流(liu)量、速度(du)(du)和(he)其他的(de)(de)(de)參數(shu)。電(dian)磁(ci)閥(fa)(fa)可以配合(he)不(bu)同(tong)的(de)(de)(de)電(dian)路(lu)來實現預(yu)期的(de)(de)(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)(de)(de)精度(du)(du)和(he)靈(ling)活性都能夠(gou)保證。電(dian)磁(ci)閥(fa)(fa)有很(hen)多種(zhong)，不(bu)同(tong)的(de)(de)(de)電(dian)磁(ci)閥(fa)(fa)在控(kong)制(zhi)系統的(de)(de)(de)不(bu)同(tong)位置發揮作用(yong)，最(zui)常用(yong)的(de)(de)(de)是(shi)單(dan)向(xiang)閥(fa)(fa)、安(an)全閥(fa)(fa)、方向(xiang)控(kong)制(zhi)閥(fa)(fa)、速度(du)(du)調節閥(fa)(fa)等。

電(dian)磁(ci)閥里(li)有密閉的(de)腔(qiang)，在不(bu)同位置(zhi)開(kai)有通(tong)孔，每個孔連接不(bu)同的(de)油(you)管，腔(qiang)中(zhong)間(jian)是(shi)活(huo)塞(sai)，兩面是(shi)兩塊(kuai)電(dian)磁(ci)鐵(tie)(tie)，哪面的(de)磁(ci)鐵(tie)(tie)線圈(quan)通(tong)電(dian)閥體就會被吸引到(dao)哪邊(bian)，通(tong)過(guo)控(kong)制(zhi)閥體的(de)移(yi)動(dong)來開(kai)啟或關閉不(bu)同的(de)排(pai)油(you)孔，而(er)進油(you)孔是(shi)常開(kai)的(de)，液壓油(you)就會進入不(bu)同的(de)排(pai)油(you)管，然后通(tong)過(guo)油(you)的(de)壓力(li)來推(tui)動(dong)油(you)缸的(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動(dong)活(huo)塞(sai)桿(gan)(gan)，活(huo)塞(sai)桿(gan)(gan)帶動(dong)機(ji)(ji)械裝置(zhi)。這樣通(tong)過(guo)控(kong)制(zhi)電(dian)磁(ci)鐵(tie)(tie)的(de)電(dian)流通(tong)斷就控(kong)制(zhi)了機(ji)(ji)械運動(dong)。

1、電磁閥從原理上分(fen)為三大(da)類：

直動式電磁(ci)閥

原理：通電(dian)時，電(dian)磁線圈產(chan)生電(dian)磁力(li)把關閉(bi)件(jian)(jian)從閥(fa)(fa)座上(shang)提起，閥(fa)(fa)門(men)打開；斷電(dian)時，電(dian)磁力(li)消失，彈簧把關閉(bi)件(jian)(jian)壓在閥(fa)(fa)座上(shang)，閥(fa)(fa)門(men)關閉(bi)。

特點：在(zai)真(zhen)空、負壓、零壓時(shi)能正常(chang)工作，但通徑一般不(bu)超過25mm。

分步直動式(shi)電磁閥(fa)

原理：它(ta)是一(yi)種(zhong)直(zhi)動(dong)和先(xian)(xian)導(dao)式相結合的原理，當入(ru)口與(yu)出口沒有壓差(cha)(cha)時，通電后，電磁力(li)直(zhi)接把先(xian)(xian)導(dao)小(xiao)閥(fa)(fa)(fa)和主(zhu)(zhu)閥(fa)(fa)(fa)關閉件(jian)依(yi)次向(xiang)上(shang)提起(qi)，閥(fa)(fa)(fa)門打開(kai)。當入(ru)口與(yu)出口達到啟動(dong)壓差(cha)(cha)時，通電后，電磁力(li)先(xian)(xian)導(dao)小(xiao)閥(fa)(fa)(fa)，主(zhu)(zhu)閥(fa)(fa)(fa)下(xia)腔壓力(li)上(shang)升，上(shang)腔壓力(li)下(xia)降，從(cong)而(er)利用壓差(cha)(cha)把主(zhu)(zhu)閥(fa)(fa)(fa)向(xiang)上(shang)推開(kai)；斷電時，先(xian)(xian)導(dao)閥(fa)(fa)(fa)利用彈(dan)簧力(li)或(huo)介質壓力(li)推動(dong)關閉件(jian)，向(xiang)下(xia)移動(dong)，使閥(fa)(fa)(fa)門關閉。

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

先導式電磁閥

原理：通電時，電磁力(li)把先(xian)導(dao)孔打開，上腔(qiang)室壓力(li)迅(xun)(xun)速下(xia)降，在(zai)關 閉件(jian)(jian)周圍(wei)形成上低下(xia)高的(de)壓差(cha)，流(liu)體壓力(li)推動關閉件(jian)(jian)向(xiang)上移動，閥門打開；斷電時，彈簧力(li)把先(xian)導(dao)孔關閉，入口(kou)壓力(li)通過旁通孔迅(xun)(xun)速腔(qiang)室在(zai)關閥件(jian)(jian)周圍(wei)形成下(xia)低上高的(de)壓差(cha)，流(liu)體壓力(li)推動關閉件(jian)(jian)向(xiang)下(xia)移動，關閉閥門。

特點：流體壓(ya)力范圍上限較高，可任意安裝（需定制）但必(bi)須滿足(zu)流體壓(ya)差(cha)條(tiao)件。

2、電磁閥從閥結構(gou)(gou)(gou)和材料上(shang)的不同與(yu)原理(li)上(shang)的區(qu)別，分(fen)為六個分(fen)支小類(lei)：直動(dong)(dong)膜片(pian)(pian)結構(gou)(gou)(gou)、分(fen)步直動(dong)(dong)膜片(pian)(pian)結構(gou)(gou)(gou)、先導膜片(pian)(pian)結構(gou)(gou)(gou)、直動(dong)(dong)活塞(sai)結構(gou)(gou)(gou)、分(fen)步直動(dong)(dong)活塞(sai)結構(gou)(gou)(gou)、先導活塞(sai)結構(gou)(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按(an)照功能分類：水用(yong)電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低(di)溫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用(yong)電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微型電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓(ya)電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油用(yong)電(dian)(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)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高(gao)壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆(bao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等。