電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是(shi)用(yong)(yong)電(dian)磁(ci)控(kong)制(zhi)的(de)工業(ye)設(she)備(bei)，是(shi)用(yong)(yong)來(lai)控(kong)制(zhi)流體的(de)自動化基礎元件，屬于執行器，并不限于液壓、氣(qi)動。用(yong)(yong)在工業(ye)控(kong)制(zhi)系(xi)統中調(diao)整介質的(de)方向(xiang)(xiang)、流量、速度(du)和其(qi)他的(de)參數。電(dian)磁(ci)閥(fa)(fa)可以配合不同(tong)的(de)電(dian)路來(lai)實現預期的(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)精度(du)和靈活性都能(neng)夠保證。電(dian)磁(ci)閥(fa)(fa)有很多(duo)種(zhong)，不同(tong)的(de)電(dian)磁(ci)閥(fa)(fa)在控(kong)制(zhi)系(xi)統的(de)不同(tong)位置發揮作用(yong)(yong)，最(zui)常用(yong)(yong)的(de)是(shi)單向(xiang)(xiang)閥(fa)(fa)、安全閥(fa)(fa)、方向(xiang)(xiang)控(kong)制(zhi)閥(fa)(fa)、速度(du)調(diao)節閥(fa)(fa)等。

電磁(ci)(ci)閥里有(you)密閉的(de)腔，在(zai)不(bu)同(tong)(tong)位(wei)置開(kai)有(you)通(tong)孔，每個孔連(lian)接不(bu)同(tong)(tong)的(de)油(you)(you)管，腔中間(jian)是活(huo)(huo)塞(sai)，兩(liang)面(mian)是兩(liang)塊電磁(ci)(ci)鐵(tie)，哪(na)面(mian)的(de)磁(ci)(ci)鐵(tie)線圈通(tong)電閥體就會(hui)被吸引到哪(na)邊，通(tong)過控制閥體的(de)移動來開(kai)啟或關閉不(bu)同(tong)(tong)的(de)排油(you)(you)孔，而進油(you)(you)孔是常開(kai)的(de)，液壓(ya)油(you)(you)就會(hui)進入不(bu)同(tong)(tong)的(de)排油(you)(you)管，然后(hou)通(tong)過油(you)(you)的(de)壓(ya)力來推動油(you)(you)缸的(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又帶動活(huo)(huo)塞(sai)桿，活(huo)(huo)塞(sai)桿帶動機械裝置。這樣通(tong)過控制電磁(ci)(ci)鐵(tie)的(de)電流通(tong)斷就控制了(le)機械運動。

1、電磁閥從原理(li)上(shang)分為(wei)三大類(lei)：

直動(dong)式電磁閥

原理：通電時，電磁線圈產(chan)生電磁力(li)把關(guan)閉件從閥座(zuo)上(shang)提起(qi)，閥門打開；斷電時，電磁力(li)消失(shi)，彈簧把關(guan)閉件壓在閥座(zuo)上(shang)，閥門關(guan)閉。

特點：在真空、負壓(ya)、零壓(ya)時能正(zheng)常工作，但通徑(jing)一(yi)般不超過25mm。

分步(bu)直(zhi)動(dong)式電磁閥

原(yuan)理(li)：它是一種直動和先(xian)導(dao)式相(xiang)結合的原(yuan)理(li)，當入口(kou)與(yu)出口(kou)沒有壓差(cha)時，通電(dian)后，電(dian)磁(ci)力直接(jie)把先(xian)導(dao)小閥(fa)(fa)(fa)(fa)和主(zhu)(zhu)閥(fa)(fa)(fa)(fa)關閉(bi)件依次向上(shang)(shang)(shang)提起，閥(fa)(fa)(fa)(fa)門打(da)開(kai)。當入口(kou)與(yu)出口(kou)達到啟(qi)動壓差(cha)時，通電(dian)后，電(dian)磁(ci)力先(xian)導(dao)小閥(fa)(fa)(fa)(fa)，主(zhu)(zhu)閥(fa)(fa)(fa)(fa)下(xia)腔壓力上(shang)(shang)(shang)升，上(shang)(shang)(shang)腔壓力下(xia)降，從而(er)利(li)用壓差(cha)把主(zhu)(zhu)閥(fa)(fa)(fa)(fa)向上(shang)(shang)(shang)推(tui)開(kai)；斷電(dian)時，先(xian)導(dao)閥(fa)(fa)(fa)(fa)利(li)用彈簧力或介質壓力推(tui)動關閉(bi)件，向下(xia)移動，使閥(fa)(fa)(fa)(fa)門關閉(bi)。

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

先(xian)導(dao)式(shi)電磁閥

原理(li)：通(tong)電(dian)時，電(dian)磁力(li)(li)把(ba)先導(dao)孔(kong)打開，上腔室壓(ya)力(li)(li)迅(xun)速下(xia)(xia)(xia)降，在(zai)(zai)關(guan)(guan) 閉(bi)件周圍形(xing)成上低下(xia)(xia)(xia)高(gao)的壓(ya)差，流體壓(ya)力(li)(li)推動(dong)關(guan)(guan)閉(bi)件向(xiang)(xiang)上移動(dong)，閥門打開；斷電(dian)時，彈簧(huang)力(li)(li)把(ba)先導(dao)孔(kong)關(guan)(guan)閉(bi)，入(ru)口壓(ya)力(li)(li)通(tong)過旁通(tong)孔(kong)迅(xun)速腔室在(zai)(zai)關(guan)(guan)閥件周圍形(xing)成下(xia)(xia)(xia)低上高(gao)的壓(ya)差，流體壓(ya)力(li)(li)推動(dong)關(guan)(guan)閉(bi)件向(xiang)(xiang)下(xia)(xia)(xia)移動(dong)，關(guan)(guan)閉(bi)閥門。

特點：流(liu)體壓力(li)范圍(wei)上限較高(gao)，可(ke)任意(yi)安(an)裝（需(xu)定制(zhi)）但必須滿足流(liu)體壓差條件(jian)。

2、電磁(ci)閥(fa)從閥(fa)結(jie)(jie)構(gou)和(he)材料上(shang)的(de)不同(tong)與原理上(shang)的(de)區(qu)別，分為六個分支小(xiao)類(lei)：直(zhi)動(dong)膜片(pian)結(jie)(jie)構(gou)、分步(bu)直(zhi)動(dong)膜片(pian)結(jie)(jie)構(gou)、先(xian)導膜片(pian)結(jie)(jie)構(gou)、直(zhi)動(dong)活(huo)(huo)塞結(jie)(jie)構(gou)、分步(bu)直(zhi)動(dong)活(huo)(huo)塞結(jie)(jie)構(gou)、先(xian)導活(huo)(huo)塞結(jie)(jie)構(gou)。

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