電(dian)(dian)磁閥(fa)(fa)(fa)（Electromagnetic valve）是(shi)用(yong)電(dian)(dian)磁控制(zhi)(zhi)的(de)(de)工(gong)業設備，是(shi)用(yong)來控制(zhi)(zhi)流(liu)體的(de)(de)自動化基礎元件，屬于執行器，并不限于液壓、氣動。用(yong)在工(gong)業控制(zhi)(zhi)系(xi)(xi)統(tong)中調整介質的(de)(de)方(fang)向(xiang)、流(liu)量(liang)、速度(du)和其他的(de)(de)參(can)數(shu)。電(dian)(dian)磁閥(fa)(fa)(fa)可以(yi)配合不同(tong)(tong)(tong)的(de)(de)電(dian)(dian)路來實現預期的(de)(de)控制(zhi)(zhi)，而控制(zhi)(zhi)的(de)(de)精度(du)和靈活性都能夠(gou)保證(zheng)。電(dian)(dian)磁閥(fa)(fa)(fa)有很多(duo)種，不同(tong)(tong)(tong)的(de)(de)電(dian)(dian)磁閥(fa)(fa)(fa)在控制(zhi)(zhi)系(xi)(xi)統(tong)的(de)(de)不同(tong)(tong)(tong)位置發揮作用(yong)，最(zui)常用(yong)的(de)(de)是(shi)單向(xiang)閥(fa)(fa)(fa)、安(an)全(quan)閥(fa)(fa)(fa)、方(fang)向(xiang)控制(zhi)(zhi)閥(fa)(fa)(fa)、速度(du)調節(jie)閥(fa)(fa)(fa)等。

電磁(ci)閥里有密閉(bi)的(de)(de)腔，在不(bu)(bu)同位(wei)置開有通(tong)孔，每個孔連接(jie)不(bu)(bu)同的(de)(de)油(you)(you)(you)管，腔中間是活(huo)(huo)塞(sai)，兩面是兩塊(kuai)電磁(ci)鐵，哪面的(de)(de)磁(ci)鐵線圈(quan)通(tong)電閥體就會(hui)被(bei)吸引到哪邊，通(tong)過控(kong)制(zhi)(zhi)閥體的(de)(de)移動(dong)(dong)來開啟或關(guan)閉(bi)不(bu)(bu)同的(de)(de)排油(you)(you)(you)孔，而(er)進油(you)(you)(you)孔是常開的(de)(de)，液壓(ya)油(you)(you)(you)就會(hui)進入不(bu)(bu)同的(de)(de)排油(you)(you)(you)管，然后(hou)通(tong)過油(you)(you)(you)的(de)(de)壓(ya)力來推動(dong)(dong)油(you)(you)(you)缸(gang)的(de)(de)活(huo)(huo)塞(sai)，活(huo)(huo)塞(sai)又帶動(dong)(dong)活(huo)(huo)塞(sai)桿，活(huo)(huo)塞(sai)桿帶動(dong)(dong)機械(xie)裝置。這(zhe)樣通(tong)過控(kong)制(zhi)(zhi)電磁(ci)鐵的(de)(de)電流通(tong)斷(duan)就控(kong)制(zhi)(zhi)了機械(xie)運動(dong)(dong)。

1、電磁閥(fa)從原(yuan)理(li)上分(fen)為三大類(lei)：

直(zhi)動式電磁(ci)閥

原理：通電(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)磁線圈產(chan)生電(dian)(dian)(dian)磁力(li)把(ba)關閉(bi)件從閥座(zuo)上(shang)提起，閥門打(da)開；斷(duan)電(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)磁力(li)消失，彈簧把(ba)關閉(bi)件壓在閥座(zuo)上(shang)，閥門關閉(bi)。

特(te)點：在真空、負(fu)壓、零壓時能(neng)正常工作(zuo)，但通徑一般(ban)不(bu)超過25mm。

分步直動(dong)式電磁(ci)閥

原理：它是一種(zhong)直(zhi)(zhi)動(dong)和(he)先導(dao)(dao)(dao)式相結合的(de)原理，當(dang)(dang)入(ru)口與出(chu)口沒有壓差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)(li)直(zhi)(zhi)接把先導(dao)(dao)(dao)小閥(fa)(fa)(fa)和(he)主閥(fa)(fa)(fa)關閉件依次向上提(ti)起，閥(fa)(fa)(fa)門打開。當(dang)(dang)入(ru)口與出(chu)口達到啟動(dong)壓差(cha)時(shi)，通電(dian)后，電(dian)磁力(li)(li)先導(dao)(dao)(dao)小閥(fa)(fa)(fa)，主閥(fa)(fa)(fa)下(xia)腔壓力(li)(li)上升，上腔壓力(li)(li)下(xia)降(jiang)，從而利用(yong)壓差(cha)把主閥(fa)(fa)(fa)向上推開；斷電(dian)時(shi)，先導(dao)(dao)(dao)閥(fa)(fa)(fa)利用(yong)彈(dan)簧(huang)力(li)(li)或介質壓力(li)(li)推動(dong)關閉件，向下(xia)移動(dong)，使閥(fa)(fa)(fa)門關閉。

特點：在零壓(ya)差或真空、高壓(ya)時(shi)亦能(neng)可*動作，但功率較大，要(yao)求必須水(shui)平安裝。

先導式電(dian)磁閥

原理：通電時，電磁力(li)把(ba)先導孔(kong)打開，上(shang)腔室(shi)壓(ya)力(li)迅(xun)(xun)速(su)下降，在關(guan)(guan) 閉件周圍(wei)(wei)形成(cheng)上(shang)低下高的(de)壓(ya)差，流體壓(ya)力(li)推動關(guan)(guan)閉件向(xiang)上(shang)移動，閥(fa)(fa)門(men)打開；斷(duan)電時，彈(dan)簧力(li)把(ba)先導孔(kong)關(guan)(guan)閉，入口壓(ya)力(li)通過(guo)旁通孔(kong)迅(xun)(xun)速(su)腔室(shi)在關(guan)(guan)閥(fa)(fa)件周圍(wei)(wei)形成(cheng)下低上(shang)高的(de)壓(ya)差，流體壓(ya)力(li)推動關(guan)(guan)閉件向(xiang)下移動，關(guan)(guan)閉閥(fa)(fa)門(men)。

特點：流(liu)體壓力范圍上限較(jiao)高，可任意(yi)安裝（需(xu)定制）但必須滿足流(liu)體壓差條件。

2、電磁閥從閥結構(gou)(gou)(gou)和材料上(shang)的不同與原理(li)上(shang)的區別，分(fen)為六個分(fen)支小類：直(zhi)動膜(mo)(mo)片結構(gou)(gou)(gou)、分(fen)步(bu)直(zhi)動膜(mo)(mo)片結構(gou)(gou)(gou)、先導(dao)膜(mo)(mo)片結構(gou)(gou)(gou)、直(zhi)動活(huo)(huo)塞結構(gou)(gou)(gou)、分(fen)步(bu)直(zhi)動活(huo)(huo)塞結構(gou)(gou)(gou)、先導(dao)活(huo)(huo)塞結構(gou)(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)按照功能分類：水(shui)用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)(fa)等(deng)。