電(dian)(dian)磁閥（Electromagnetic valve）是用(yong)電(dian)(dian)磁控(kong)(kong)(kong)制(zhi)的(de)(de)工業(ye)設備(bei)，是用(yong)來控(kong)(kong)(kong)制(zhi)流體的(de)(de)自動(dong)化基礎元件(jian)，屬于執(zhi)行器，并不(bu)限于液壓(ya)、氣動(dong)。用(yong)在工業(ye)控(kong)(kong)(kong)制(zhi)系統中調整介質的(de)(de)方向、流量、速度(du)(du)和其他的(de)(de)參數。電(dian)(dian)磁閥可以(yi)配(pei)合不(bu)同(tong)的(de)(de)電(dian)(dian)路來實(shi)現預期的(de)(de)控(kong)(kong)(kong)制(zhi)，而控(kong)(kong)(kong)制(zhi)的(de)(de)精(jing)度(du)(du)和靈活性都能(neng)夠(gou)保證。電(dian)(dian)磁閥有很多種，不(bu)同(tong)的(de)(de)電(dian)(dian)磁閥在控(kong)(kong)(kong)制(zhi)系統的(de)(de)不(bu)同(tong)位置發揮作用(yong)，最常用(yong)的(de)(de)是單向閥、安(an)全閥、方向控(kong)(kong)(kong)制(zhi)閥、速度(du)(du)調節閥等(deng)。

電(dian)磁閥里有(you)密閉的(de)(de)腔，在不(bu)同位置(zhi)開有(you)通(tong)(tong)孔(kong)(kong)，每個孔(kong)(kong)連接不(bu)同的(de)(de)油(you)(you)管(guan)，腔中間(jian)是活(huo)塞(sai)，兩面是兩塊電(dian)磁鐵(tie)，哪(na)面的(de)(de)磁鐵(tie)線圈通(tong)(tong)電(dian)閥體就會被吸引到哪(na)邊，通(tong)(tong)過(guo)(guo)控制(zhi)閥體的(de)(de)移動(dong)來開啟或關閉不(bu)同的(de)(de)排油(you)(you)孔(kong)(kong)，而進油(you)(you)孔(kong)(kong)是常開的(de)(de)，液壓油(you)(you)就會進入(ru)不(bu)同的(de)(de)排油(you)(you)管(guan)，然后通(tong)(tong)過(guo)(guo)油(you)(you)的(de)(de)壓力來推(tui)動(dong)油(you)(you)缸(gang)的(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動(dong)活(huo)塞(sai)桿(gan)，活(huo)塞(sai)桿(gan)帶動(dong)機械(xie)(xie)裝置(zhi)。這樣通(tong)(tong)過(guo)(guo)控制(zhi)電(dian)磁鐵(tie)的(de)(de)電(dian)流通(tong)(tong)斷(duan)就控制(zhi)了機械(xie)(xie)運(yun)動(dong)。

1、電(dian)磁閥從原理上分為(wei)三大類：

直動式電磁閥

原理：通電(dian)時，電(dian)磁線(xian)圈產生電(dian)磁力把關(guan)閉件從閥(fa)(fa)(fa)座上提起，閥(fa)(fa)(fa)門(men)打(da)開(kai)；斷電(dian)時，電(dian)磁力消失，彈(dan)簧把關(guan)閉件壓在閥(fa)(fa)(fa)座上，閥(fa)(fa)(fa)門(men)關(guan)閉。

特點：在真空、負壓、零壓時能正常(chang)工作，但通徑(jing)一般(ban)不超過25mm。

分步(bu)直(zhi)動(dong)式電磁閥

原理：它是一種直(zhi)動(dong)(dong)和先(xian)(xian)導(dao)(dao)式相結(jie)合的(de)原理，當入口與出口沒有壓差(cha)時，通電(dian)后，電(dian)磁力(li)(li)直(zhi)接把(ba)先(xian)(xian)導(dao)(dao)小閥(fa)和主閥(fa)關(guan)閉件依次(ci)向上(shang)(shang)(shang)提起，閥(fa)門(men)打開。當入口與出口達(da)到(dao)啟動(dong)(dong)壓差(cha)時，通電(dian)后，電(dian)磁力(li)(li)先(xian)(xian)導(dao)(dao)小閥(fa)，主閥(fa)下(xia)(xia)腔(qiang)壓力(li)(li)上(shang)(shang)(shang)升，上(shang)(shang)(shang)腔(qiang)壓力(li)(li)下(xia)(xia)降(jiang)，從而利用壓差(cha)把(ba)主閥(fa)向上(shang)(shang)(shang)推開；斷電(dian)時，先(xian)(xian)導(dao)(dao)閥(fa)利用彈簧力(li)(li)或(huo)介質壓力(li)(li)推動(dong)(dong)關(guan)閉件，向下(xia)(xia)移動(dong)(dong)，使(shi)閥(fa)門(men)關(guan)閉。

特點(dian)：在(zai)零壓差或真(zhen)空、高壓時亦(yi)能可*動作(zuo)，但功率較大，要求必須水(shui)平安裝。

先(xian)導式電磁閥

原理：通(tong)電(dian)時(shi)，電(dian)磁力把先導孔(kong)打開，上腔室壓(ya)力迅(xun)速下(xia)降，在(zai)關 閉(bi)(bi)(bi)(bi)件(jian)周(zhou)圍(wei)形(xing)成上低下(xia)高的壓(ya)差，流體壓(ya)力推(tui)動關閉(bi)(bi)(bi)(bi)件(jian)向上移(yi)動，閥門打開；斷電(dian)時(shi)，彈簧(huang)力把先導孔(kong)關閉(bi)(bi)(bi)(bi)，入口壓(ya)力通(tong)過旁通(tong)孔(kong)迅(xun)速腔室在(zai)關閥件(jian)周(zhou)圍(wei)形(xing)成下(xia)低上高的壓(ya)差，流體壓(ya)力推(tui)動關閉(bi)(bi)(bi)(bi)件(jian)向下(xia)移(yi)動，關閉(bi)(bi)(bi)(bi)閥門。

特點：流(liu)體(ti)壓(ya)力范(fan)圍(wei)上限較高，可任(ren)意安裝（需(xu)定(ding)制）但必須滿足流(liu)體(ti)壓(ya)差(cha)條件。

2、電磁閥(fa)從閥(fa)結構(gou)和材料上的(de)不(bu)同與原理上的(de)區別，分為六個分支(zhi)小類：直動(dong)膜片結構(gou)、分步直動(dong)膜片結構(gou)、先導膜片結構(gou)、直動(dong)活塞(sai)結構(gou)、分步直動(dong)活塞(sai)結構(gou)、先導活塞(sai)結構(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)按(an)照功能分(fen)類：水用電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、燃(ran)氣電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、消防(fang)(fang)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、脈(mo)沖電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa) 常(chang)開(kai)電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、防(fang)(fang)爆電(dian)(dian)(dian)(dian)磁(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)等。