電(dian)磁(ci)閥(fa)(fa)(fa)（Electromagnetic valve）是(shi)(shi)用(yong)電(dian)磁(ci)控(kong)(kong)(kong)制的(de)工業(ye)設備，是(shi)(shi)用(yong)來控(kong)(kong)(kong)制流體的(de)自動化基礎元件，屬于執(zhi)行器，并不限于液壓、氣動。用(yong)在(zai)工業(ye)控(kong)(kong)(kong)制系統中(zhong)調(diao)整(zheng)介(jie)質(zhi)的(de)方向、流量、速度和其他的(de)參數(shu)。電(dian)磁(ci)閥(fa)(fa)(fa)可以配合不同(tong)的(de)電(dian)路(lu)來實現預期的(de)控(kong)(kong)(kong)制，而控(kong)(kong)(kong)制的(de)精度和靈(ling)活(huo)性都能(neng)夠保證。電(dian)磁(ci)閥(fa)(fa)(fa)有很(hen)多種(zhong)，不同(tong)的(de)電(dian)磁(ci)閥(fa)(fa)(fa)在(zai)控(kong)(kong)(kong)制系統的(de)不同(tong)位置發揮作用(yong)，最常用(yong)的(de)是(shi)(shi)單(dan)向閥(fa)(fa)(fa)、安全閥(fa)(fa)(fa)、方向控(kong)(kong)(kong)制閥(fa)(fa)(fa)、速度調(diao)節(jie)閥(fa)(fa)(fa)等。

電(dian)(dian)(dian)磁閥里有密(mi)閉的(de)腔，在(zai)不同(tong)位置開(kai)有通(tong)(tong)孔，每(mei)個孔連接不同(tong)的(de)油管(guan)，腔中(zhong)間是活(huo)(huo)塞(sai)(sai)，兩面是兩塊電(dian)(dian)(dian)磁鐵(tie)，哪(na)面的(de)磁鐵(tie)線(xian)圈(quan)通(tong)(tong)電(dian)(dian)(dian)閥體就(jiu)會被吸(xi)引到(dao)哪(na)邊(bian)，通(tong)(tong)過控(kong)制閥體的(de)移動(dong)來開(kai)啟或(huo)關(guan)閉不同(tong)的(de)排油孔，而進油孔是常開(kai)的(de)，液壓油就(jiu)會進入不同(tong)的(de)排油管(guan)，然后通(tong)(tong)過油的(de)壓力來推動(dong)油缸的(de)活(huo)(huo)塞(sai)(sai)，活(huo)(huo)塞(sai)(sai)又(you)帶動(dong)活(huo)(huo)塞(sai)(sai)桿，活(huo)(huo)塞(sai)(sai)桿帶動(dong)機械(xie)裝(zhuang)置。這樣通(tong)(tong)過控(kong)制電(dian)(dian)(dian)磁鐵(tie)的(de)電(dian)(dian)(dian)流通(tong)(tong)斷就(jiu)控(kong)制了(le)機械(xie)運動(dong)。

1、電磁閥從原理上分為三大類：

直動式電磁閥(fa)

原(yuan)理：通電(dian)時(shi)，電(dian)磁(ci)線圈產生(sheng)電(dian)磁(ci)力把關閉(bi)件從閥(fa)(fa)座(zuo)上提起，閥(fa)(fa)門打(da)開；斷電(dian)時(shi)，電(dian)磁(ci)力消失(shi)，彈簧把關閉(bi)件壓在(zai)閥(fa)(fa)座(zuo)上，閥(fa)(fa)門關閉(bi)。

特點：在真(zhen)空、負壓、零(ling)壓時(shi)能(neng)正常(chang)工作，但通徑一般(ban)不超過25mm。

分(fen)步直動式電磁閥

原理：它(ta)是一種直(zhi)動(dong)和先導(dao)式相(xiang)結(jie)合的(de)原理，當(dang)(dang)入口(kou)與(yu)出口(kou)沒(mei)有壓(ya)差時(shi)，通電(dian)(dian)后，電(dian)(dian)磁力(li)直(zhi)接把先導(dao)小閥和主(zhu)閥關閉件依次向上提起，閥門(men)打開(kai)。當(dang)(dang)入口(kou)與(yu)出口(kou)達到(dao)啟動(dong)壓(ya)差時(shi)，通電(dian)(dian)后，電(dian)(dian)磁力(li)先導(dao)小閥，主(zhu)閥下腔壓(ya)力(li)上升，上腔壓(ya)力(li)下降，從(cong)而利用(yong)壓(ya)差把主(zhu)閥向上推(tui)開(kai)；斷(duan)電(dian)(dian)時(shi)，先導(dao)閥利用(yong)彈簧(huang)力(li)或介質(zhi)壓(ya)力(li)推(tui)動(dong)關閉件，向下移動(dong)，使閥門(men)關閉。

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

先導式電(dian)磁閥

原理(li)：通(tong)電(dian)時，電(dian)磁力把先導孔打開，上(shang)腔室(shi)壓(ya)(ya)(ya)(ya)力迅(xun)速下(xia)降，在(zai)(zai)關(guan)(guan) 閉(bi)件(jian)周圍形成上(shang)低下(xia)高(gao)(gao)的(de)壓(ya)(ya)(ya)(ya)差，流體(ti)壓(ya)(ya)(ya)(ya)力推動(dong)關(guan)(guan)閉(bi)件(jian)向上(shang)移動(dong)，閥(fa)門打開；斷(duan)電(dian)時，彈簧(huang)力把先導孔關(guan)(guan)閉(bi)，入(ru)口壓(ya)(ya)(ya)(ya)力通(tong)過旁(pang)通(tong)孔迅(xun)速腔室(shi)在(zai)(zai)關(guan)(guan)閥(fa)件(jian)周圍形成下(xia)低上(shang)高(gao)(gao)的(de)壓(ya)(ya)(ya)(ya)差，流體(ti)壓(ya)(ya)(ya)(ya)力推動(dong)關(guan)(guan)閉(bi)件(jian)向下(xia)移動(dong)，關(guan)(guan)閉(bi)閥(fa)門。

特點：流體壓力范(fan)圍上(shang)限較高(gao)，可任(ren)意安(an)裝（需定制）但必須(xu)滿(man)足流體壓差條件。

2、電磁閥從閥結(jie)構(gou)和材料上(shang)的不同與原理(li)上(shang)的區別，分(fen)(fen)為(wei)六(liu)個分(fen)(fen)支小類：直(zhi)動(dong)(dong)膜片結(jie)構(gou)、分(fen)(fen)步直(zhi)動(dong)(dong)膜片結(jie)構(gou)、先(xian)導(dao)膜片結(jie)構(gou)、直(zhi)動(dong)(dong)活塞結(jie)構(gou)、分(fen)(fen)步直(zhi)動(dong)(dong)活塞結(jie)構(gou)、先(xian)導(dao)活塞結(jie)構(gou)。

3、電(dian)(dian)磁(ci)(ci)(ci)閥按照功能分類：水(shui)用電(dian)(dian)磁(ci)(ci)(ci)閥、蒸汽(qi)電(dian)(dian)磁(ci)(ci)(ci)閥、制冷(leng)電(dian)(dian)磁(ci)(ci)(ci)閥、低溫電(dian)(dian)磁(ci)(ci)(ci)閥、燃氣電(dian)(dian)磁(ci)(ci)(ci)閥、消防電(dian)(dian)磁(ci)(ci)(ci)閥、氨用電(dian)(dian)磁(ci)(ci)(ci)閥、氣體電(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)體電(dian)(dian)磁(ci)(ci)(ci)閥、微型電(dian)(dian)磁(ci)(ci)(ci)閥、脈沖電(dian)(dian)磁(ci)(ci)(ci)閥、液(ye)壓電(dian)(dian)磁(ci)(ci)(ci)閥 常開電(dian)(dian)磁(ci)(ci)(ci)閥、油(you)用電(dian)(dian)磁(ci)(ci)(ci)閥、直流電(dian)(dian)磁(ci)(ci)(ci)閥、高壓電(dian)(dian)磁(ci)(ci)(ci)閥、防爆電(dian)(dian)磁(ci)(ci)(ci)閥等。