電(dian)(dian)(dian)磁閥（Electromagnetic valve）是(shi)用電(dian)(dian)(dian)磁控(kong)制(zhi)(zhi)的(de)(de)工(gong)業設(she)備，是(shi)用來(lai)控(kong)制(zhi)(zhi)流(liu)體的(de)(de)自動(dong)化基礎元(yuan)件(jian)，屬于執行器，并不(bu)限于液(ye)壓、氣動(dong)。用在(zai)(zai)工(gong)業控(kong)制(zhi)(zhi)系統中調(diao)整(zheng)介質的(de)(de)方向(xiang)、流(liu)量、速(su)度(du)(du)和(he)其他的(de)(de)參(can)數。電(dian)(dian)(dian)磁閥可(ke)以配合不(bu)同的(de)(de)電(dian)(dian)(dian)路來(lai)實(shi)現(xian)預(yu)期的(de)(de)控(kong)制(zhi)(zhi)，而(er)控(kong)制(zhi)(zhi)的(de)(de)精(jing)度(du)(du)和(he)靈(ling)活(huo)性都能夠保證。電(dian)(dian)(dian)磁閥有很多種，不(bu)同的(de)(de)電(dian)(dian)(dian)磁閥在(zai)(zai)控(kong)制(zhi)(zhi)系統的(de)(de)不(bu)同位置發(fa)揮作用，最常用的(de)(de)是(shi)單向(xiang)閥、安全(quan)閥、方向(xiang)控(kong)制(zhi)(zhi)閥、速(su)度(du)(du)調(diao)節閥等(deng)。

電磁閥(fa)里有密閉的(de)(de)腔，在不(bu)同(tong)位置開有通(tong)(tong)(tong)孔(kong)，每(mei)個孔(kong)連(lian)接不(bu)同(tong)的(de)(de)油(you)(you)管，腔中間是活塞(sai)(sai)，兩面(mian)是兩塊電磁鐵(tie)，哪(na)(na)面(mian)的(de)(de)磁鐵(tie)線圈通(tong)(tong)(tong)電閥(fa)體就會被吸引到哪(na)(na)邊，通(tong)(tong)(tong)過控制閥(fa)體的(de)(de)移動(dong)(dong)(dong)(dong)來開啟(qi)或關閉不(bu)同(tong)的(de)(de)排(pai)油(you)(you)孔(kong)，而(er)進(jin)油(you)(you)孔(kong)是常開的(de)(de)，液壓油(you)(you)就會進(jin)入不(bu)同(tong)的(de)(de)排(pai)油(you)(you)管，然后通(tong)(tong)(tong)過油(you)(you)的(de)(de)壓力來推動(dong)(dong)(dong)(dong)油(you)(you)缸的(de)(de)活塞(sai)(sai)，活塞(sai)(sai)又帶動(dong)(dong)(dong)(dong)活塞(sai)(sai)桿，活塞(sai)(sai)桿帶動(dong)(dong)(dong)(dong)機(ji)械裝置。這樣通(tong)(tong)(tong)過控制電磁鐵(tie)的(de)(de)電流通(tong)(tong)(tong)斷就控制了機(ji)械運動(dong)(dong)(dong)(dong)。

1、電磁閥從(cong)原理上分為三(san)大(da)類(lei)：

直動式電磁閥

原理：通電時，電磁(ci)線圈(quan)產生電磁(ci)力把關閉(bi)件從閥座上提起，閥門(men)打開；斷(duan)電時，電磁(ci)力消(xiao)失，彈(dan)簧(huang)把關閉(bi)件壓在閥座上，閥門(men)關閉(bi)。

特點：在真空、負壓、零(ling)壓時能(neng)正(zheng)常工作，但通徑一(yi)般不(bu)超過25mm。

分步直(zhi)動式電磁閥

原(yuan)理：它是一種直動和(he)先(xian)(xian)導式相結合的(de)原(yuan)理，當入(ru)(ru)口(kou)(kou)與(yu)出(chu)口(kou)(kou)沒有壓(ya)差(cha)時，通電(dian)后(hou)，電(dian)磁力直接(jie)把先(xian)(xian)導小閥(fa)和(he)主(zhu)閥(fa)關(guan)閉件(jian)依次向上提起，閥(fa)門(men)打開。當入(ru)(ru)口(kou)(kou)與(yu)出(chu)口(kou)(kou)達到啟動壓(ya)差(cha)時，通電(dian)后(hou)，電(dian)磁力先(xian)(xian)導小閥(fa)，主(zhu)閥(fa)下(xia)腔(qiang)壓(ya)力上升，上腔(qiang)壓(ya)力下(xia)降(jiang)，從而利用(yong)壓(ya)差(cha)把主(zhu)閥(fa)向上推開；斷(duan)電(dian)時，先(xian)(xian)導閥(fa)利用(yong)彈簧力或介質壓(ya)力推動關(guan)閉件(jian)，向下(xia)移動，使閥(fa)門(men)關(guan)閉。

特點(dian)：在零壓(ya)差(cha)或真空、高壓(ya)時亦能(neng)可*動作，但功率較大，要求(qiu)必須水平安(an)裝(zhuang)。

先導式(shi)電磁閥

原理(li)：通電時，電磁力(li)(li)把先導孔(kong)打開(kai)，上(shang)腔室壓(ya)力(li)(li)迅速下降，在關(guan) 閉件周(zhou)圍形成上(shang)低(di)下高的壓(ya)差，流體壓(ya)力(li)(li)推動關(guan)閉件向(xiang)上(shang)移(yi)(yi)動，閥門(men)打開(kai)；斷(duan)電時，彈(dan)簧(huang)力(li)(li)把先導孔(kong)關(guan)閉，入(ru)口壓(ya)力(li)(li)通過旁通孔(kong)迅速腔室在關(guan)閥件周(zhou)圍形成下低(di)上(shang)高的壓(ya)差，流體壓(ya)力(li)(li)推動關(guan)閉件向(xiang)下移(yi)(yi)動，關(guan)閉閥門(men)。

特點：流體(ti)(ti)壓(ya)力(li)范圍上(shang)限(xian)較高，可任意安裝（需定制(zhi)）但必須滿(man)足流體(ti)(ti)壓(ya)差(cha)條(tiao)件(jian)。

2、電磁閥(fa)從閥(fa)結(jie)(jie)(jie)構和材料上(shang)的(de)不同與原理(li)上(shang)的(de)區別，分為六個(ge)分支小類：直(zhi)動膜(mo)片(pian)(pian)結(jie)(jie)(jie)構、分步直(zhi)動膜(mo)片(pian)(pian)結(jie)(jie)(jie)構、先(xian)導膜(mo)片(pian)(pian)結(jie)(jie)(jie)構、直(zhi)動活(huo)(huo)塞(sai)結(jie)(jie)(jie)構、分步直(zhi)動活(huo)(huo)塞(sai)結(jie)(jie)(jie)構、先(xian)導活(huo)(huo)塞(sai)結(jie)(jie)(jie)構。

3、電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)按照功能分(fen)類：水用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、消(xiao)防(fang)(fang)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、氨(an)用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、氣體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、液壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、高(gao)壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)、防(fang)(fang)爆(bao)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)等(deng)。