電(dian)(dian)磁閥（Electromagnetic valve）是(shi)(shi)(shi)用電(dian)(dian)磁控(kong)(kong)制(zhi)(zhi)的工(gong)業設備，是(shi)(shi)(shi)用來控(kong)(kong)制(zhi)(zhi)流體的自動化基礎元件，屬于執行(xing)器(qi)，并不(bu)限于液壓(ya)、氣動。用在工(gong)業控(kong)(kong)制(zhi)(zhi)系(xi)統(tong)(tong)中調整介質的方(fang)向、流量、速度和(he)其(qi)他的參(can)數。電(dian)(dian)磁閥可以(yi)配合不(bu)同的電(dian)(dian)路來實現預期的控(kong)(kong)制(zhi)(zhi)，而(er)控(kong)(kong)制(zhi)(zhi)的精度和(he)靈(ling)活性都能(neng)夠保證。電(dian)(dian)磁閥有(you)很多(duo)種(zhong)，不(bu)同的電(dian)(dian)磁閥在控(kong)(kong)制(zhi)(zhi)系(xi)統(tong)(tong)的不(bu)同位(wei)置發揮作用，最常(chang)用的是(shi)(shi)(shi)單向閥、安(an)全閥、方(fang)向控(kong)(kong)制(zhi)(zhi)閥、速度調節閥等(deng)。

電(dian)磁閥(fa)(fa)里有密閉(bi)的(de)(de)(de)(de)腔，在不同(tong)(tong)位置開(kai)有通(tong)(tong)(tong)孔，每個孔連(lian)接不同(tong)(tong)的(de)(de)(de)(de)油(you)(you)管，腔中間是(shi)活(huo)塞(sai)，兩(liang)面是(shi)兩(liang)塊電(dian)磁鐵(tie)(tie)，哪(na)面的(de)(de)(de)(de)磁鐵(tie)(tie)線圈(quan)通(tong)(tong)(tong)電(dian)閥(fa)(fa)體(ti)(ti)就會(hui)(hui)被吸引到(dao)哪(na)邊，通(tong)(tong)(tong)過控(kong)制(zhi)閥(fa)(fa)體(ti)(ti)的(de)(de)(de)(de)移動來開(kai)啟或關閉(bi)不同(tong)(tong)的(de)(de)(de)(de)排(pai)油(you)(you)孔，而進油(you)(you)孔是(shi)常(chang)開(kai)的(de)(de)(de)(de)，液壓油(you)(you)就會(hui)(hui)進入不同(tong)(tong)的(de)(de)(de)(de)排(pai)油(you)(you)管，然后通(tong)(tong)(tong)過油(you)(you)的(de)(de)(de)(de)壓力來推動油(you)(you)缸(gang)的(de)(de)(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動活(huo)塞(sai)桿(gan)，活(huo)塞(sai)桿(gan)帶動機械(xie)裝(zhuang)置。這樣通(tong)(tong)(tong)過控(kong)制(zhi)電(dian)磁鐵(tie)(tie)的(de)(de)(de)(de)電(dian)流通(tong)(tong)(tong)斷就控(kong)制(zhi)了機械(xie)運動。

1、電(dian)磁閥(fa)從原理(li)上分為三大類：

直動式電磁(ci)閥

原理：通電時(shi)，電磁(ci)線圈產生電磁(ci)力把(ba)關閉(bi)(bi)件(jian)從閥座上提起，閥門打開；斷電時(shi)，電磁(ci)力消失，彈簧把(ba)關閉(bi)(bi)件(jian)壓在(zai)閥座上，閥門關閉(bi)(bi)。

特點：在真(zhen)空(kong)、負(fu)壓、零壓時能正常工作，但通徑一般(ban)不超過25mm。

分步直動(dong)式電磁閥

原理(li)：它是(shi)一(yi)種直(zhi)動和先導(dao)式相結合的原理(li)，當(dang)入(ru)口(kou)(kou)與出口(kou)(kou)沒有壓(ya)差(cha)(cha)時，通電(dian)后，電(dian)磁力(li)(li)直(zhi)接把先導(dao)小閥(fa)(fa)(fa)(fa)和主(zhu)閥(fa)(fa)(fa)(fa)關閉件依(yi)次(ci)向(xiang)上提起，閥(fa)(fa)(fa)(fa)門打開(kai)。當(dang)入(ru)口(kou)(kou)與出口(kou)(kou)達到啟動壓(ya)差(cha)(cha)時，通電(dian)后，電(dian)磁力(li)(li)先導(dao)小閥(fa)(fa)(fa)(fa)，主(zhu)閥(fa)(fa)(fa)(fa)下腔壓(ya)力(li)(li)上升，上腔壓(ya)力(li)(li)下降，從而利用壓(ya)差(cha)(cha)把主(zhu)閥(fa)(fa)(fa)(fa)向(xiang)上推(tui)開(kai)；斷電(dian)時，先導(dao)閥(fa)(fa)(fa)(fa)利用彈簧(huang)力(li)(li)或介(jie)質壓(ya)力(li)(li)推(tui)動關閉件，向(xiang)下移動，使閥(fa)(fa)(fa)(fa)門關閉。

特(te)點(dian)：在零壓(ya)(ya)差或真空、高壓(ya)(ya)時亦(yi)能可*動作(zuo)，但功(gong)率較大，要(yao)求必須(xu)水平安裝。

先導(dao)式電(dian)磁閥

原理：通電時，電磁力(li)把(ba)先(xian)導孔(kong)(kong)打(da)開(kai)，上(shang)(shang)腔室壓力(li)迅速(su)下降，在(zai)關(guan)(guan) 閉(bi)件周(zhou)圍(wei)形(xing)(xing)成上(shang)(shang)低下高(gao)的壓差，流體壓力(li)推動(dong)關(guan)(guan)閉(bi)件向上(shang)(shang)移(yi)動(dong)，閥(fa)門(men)打(da)開(kai)；斷電時，彈簧力(li)把(ba)先(xian)導孔(kong)(kong)關(guan)(guan)閉(bi)，入口(kou)壓力(li)通過旁通孔(kong)(kong)迅速(su)腔室在(zai)關(guan)(guan)閥(fa)件周(zhou)圍(wei)形(xing)(xing)成下低上(shang)(shang)高(gao)的壓差，流體壓力(li)推動(dong)關(guan)(guan)閉(bi)件向下移(yi)動(dong)，關(guan)(guan)閉(bi)閥(fa)門(men)。

特點：流(liu)體壓力范圍上限(xian)較高(gao)，可(ke)任意安裝（需定制）但必須滿足流(liu)體壓差條件。

2、電磁(ci)閥(fa)從(cong)閥(fa)結(jie)構(gou)和材(cai)料上的(de)不同與原理上的(de)區別，分(fen)為六個(ge)分(fen)支小類：直(zhi)動膜片結(jie)構(gou)、分(fen)步直(zhi)動膜片結(jie)構(gou)、先導膜片結(jie)構(gou)、直(zhi)動活塞結(jie)構(gou)、分(fen)步直(zhi)動活塞結(jie)構(gou)、先導活塞結(jie)構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按照功能分類：水用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸(zheng)汽(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低(di)溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微(wei)型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa) 常開(kai)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等(deng)。