電(dian)(dian)(dian)磁(ci)閥（Electromagnetic valve）是(shi)用(yong)電(dian)(dian)(dian)磁(ci)控(kong)制(zhi)的(de)(de)工業(ye)設備，是(shi)用(yong)來控(kong)制(zhi)流(liu)體的(de)(de)自(zi)動化基礎元件，屬于執(zhi)行器(qi)，并不(bu)(bu)(bu)限于液壓、氣動。用(yong)在工業(ye)控(kong)制(zhi)系統中調整(zheng)介質的(de)(de)方(fang)(fang)向、流(liu)量、速度(du)和(he)其他的(de)(de)參數。電(dian)(dian)(dian)磁(ci)閥可以配合不(bu)(bu)(bu)同的(de)(de)電(dian)(dian)(dian)路來實現預期的(de)(de)控(kong)制(zhi)，而控(kong)制(zhi)的(de)(de)精度(du)和(he)靈活性(xing)都能(neng)夠保(bao)證。電(dian)(dian)(dian)磁(ci)閥有很多種，不(bu)(bu)(bu)同的(de)(de)電(dian)(dian)(dian)磁(ci)閥在控(kong)制(zhi)系統的(de)(de)不(bu)(bu)(bu)同位置發揮(hui)作用(yong)，最常用(yong)的(de)(de)是(shi)單向閥、安(an)全閥、方(fang)(fang)向控(kong)制(zhi)閥、速度(du)調節閥等。

電(dian)(dian)磁(ci)閥(fa)里(li)有密閉的(de)腔，在不(bu)同位置開有通(tong)(tong)孔，每個(ge)孔連接不(bu)同的(de)油(you)(you)管(guan)，腔中間(jian)是(shi)活(huo)(huo)塞(sai)，兩(liang)面是(shi)兩(liang)塊(kuai)電(dian)(dian)磁(ci)鐵(tie)，哪(na)面的(de)磁(ci)鐵(tie)線(xian)圈(quan)通(tong)(tong)電(dian)(dian)閥(fa)體(ti)(ti)就會被吸引到哪(na)邊(bian)，通(tong)(tong)過控制閥(fa)體(ti)(ti)的(de)移動(dong)來開啟或(huo)關閉不(bu)同的(de)排(pai)油(you)(you)孔，而進(jin)油(you)(you)孔是(shi)常開的(de)，液壓(ya)油(you)(you)就會進(jin)入不(bu)同的(de)排(pai)油(you)(you)管(guan)，然后(hou)通(tong)(tong)過油(you)(you)的(de)壓(ya)力來推動(dong)油(you)(you)缸的(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又帶動(dong)活(huo)(huo)塞(sai)桿(gan)，活(huo)(huo)塞(sai)桿(gan)帶動(dong)機械裝置。這樣通(tong)(tong)過控制電(dian)(dian)磁(ci)鐵(tie)的(de)電(dian)(dian)流通(tong)(tong)斷就控制了機械運動(dong)。

1、電磁閥(fa)從原理上(shang)分為三大類：

直(zhi)動式(shi)電磁閥(fa)

原(yuan)理：通電(dian)(dian)時，電(dian)(dian)磁(ci)線圈產生電(dian)(dian)磁(ci)力(li)(li)把(ba)關(guan)閉(bi)件從閥座(zuo)上提(ti)起，閥門(men)打開；斷(duan)電(dian)(dian)時，電(dian)(dian)磁(ci)力(li)(li)消失，彈簧把(ba)關(guan)閉(bi)件壓在閥座(zuo)上，閥門(men)關(guan)閉(bi)。

特點：在真空、負壓、零壓時能正常工(gong)作(zuo)，但通徑(jing)一般不(bu)超過(guo)25mm。

分步直動式(shi)電磁閥

原(yuan)理：它是一種直(zhi)動和(he)先(xian)導式相(xiang)結合的(de)原(yuan)理，當入(ru)(ru)口(kou)(kou)與出口(kou)(kou)沒有壓(ya)差(cha)時，通(tong)電(dian)后(hou)，電(dian)磁力(li)直(zhi)接把先(xian)導小閥(fa)(fa)和(he)主(zhu)閥(fa)(fa)關閉(bi)件依次向(xiang)(xiang)上(shang)(shang)提(ti)起(qi)，閥(fa)(fa)門(men)打開。當入(ru)(ru)口(kou)(kou)與出口(kou)(kou)達到啟動壓(ya)差(cha)時，通(tong)電(dian)后(hou)，電(dian)磁力(li)先(xian)導小閥(fa)(fa)，主(zhu)閥(fa)(fa)下(xia)腔(qiang)壓(ya)力(li)上(shang)(shang)升，上(shang)(shang)腔(qiang)壓(ya)力(li)下(xia)降(jiang)，從而利用壓(ya)差(cha)把主(zhu)閥(fa)(fa)向(xiang)(xiang)上(shang)(shang)推開；斷電(dian)時，先(xian)導閥(fa)(fa)利用彈簧力(li)或介質(zhi)壓(ya)力(li)推動關閉(bi)件，向(xiang)(xiang)下(xia)移動，使閥(fa)(fa)門(men)關閉(bi)。

特點：在零壓差或真空、高壓時(shi)亦(yi)能可*動作，但功率(lv)較大(da)，要求必須(xu)水平安裝。

先導(dao)式(shi)電磁閥

原理：通電(dian)時(shi)，電(dian)磁力(li)(li)把(ba)先導(dao)孔(kong)(kong)打(da)開(kai)，上腔室壓(ya)力(li)(li)迅(xun)速下降，在(zai)關 閉(bi)件周圍(wei)形成上低(di)下高(gao)的壓(ya)差(cha)，流體壓(ya)力(li)(li)推(tui)動關閉(bi)件向上移(yi)動，閥(fa)門(men)打(da)開(kai)；斷電(dian)時(shi)，彈簧力(li)(li)把(ba)先導(dao)孔(kong)(kong)關閉(bi)，入口壓(ya)力(li)(li)通過(guo)旁通孔(kong)(kong)迅(xun)速腔室在(zai)關閥(fa)件周圍(wei)形成下低(di)上高(gao)的壓(ya)差(cha)，流體壓(ya)力(li)(li)推(tui)動關閉(bi)件向下移(yi)動，關閉(bi)閥(fa)門(men)。

特點：流體壓(ya)力(li)范圍上限較高，可任意安裝(zhuang)（需定制）但必須滿足流體壓(ya)差(cha)條件(jian)。

2、電(dian)磁閥從(cong)閥結(jie)構(gou)(gou)和材(cai)料(liao)上的不同與原理上的區別，分(fen)為六個分(fen)支小類(lei)：直動(dong)膜(mo)片結(jie)構(gou)(gou)、分(fen)步直動(dong)膜(mo)片結(jie)構(gou)(gou)、先導膜(mo)片結(jie)構(gou)(gou)、直動(dong)活塞(sai)(sai)結(jie)構(gou)(gou)、分(fen)步直動(dong)活塞(sai)(sai)結(jie)構(gou)(gou)、先導活塞(sai)(sai)結(jie)構(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按(an)照功能分類：水(shui)用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制(zhi)冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消防(fang)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常開(kai)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防(fang)爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等。