電(dian)(dian)磁(ci)(ci)閥(fa)（Electromagnetic valve）是用(yong)電(dian)(dian)磁(ci)(ci)控(kong)(kong)制(zhi)(zhi)的(de)(de)工(gong)業(ye)設備，是用(yong)來控(kong)(kong)制(zhi)(zhi)流(liu)體的(de)(de)自(zi)動化基礎元件，屬(shu)于執行器，并不限于液壓、氣動。用(yong)在工(gong)業(ye)控(kong)(kong)制(zhi)(zhi)系(xi)統(tong)中調(diao)整介(jie)質的(de)(de)方向、流(liu)量、速度(du)和其他(ta)的(de)(de)參數。電(dian)(dian)磁(ci)(ci)閥(fa)可以(yi)配(pei)合(he)不同(tong)的(de)(de)電(dian)(dian)路來實現預期的(de)(de)控(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)的(de)(de)精度(du)和靈(ling)活性都能(neng)夠(gou)保(bao)證(zheng)。電(dian)(dian)磁(ci)(ci)閥(fa)有(you)很多種，不同(tong)的(de)(de)電(dian)(dian)磁(ci)(ci)閥(fa)在控(kong)(kong)制(zhi)(zhi)系(xi)統(tong)的(de)(de)不同(tong)位置(zhi)發揮(hui)作用(yong)，最常用(yong)的(de)(de)是單向閥(fa)、安全閥(fa)、方向控(kong)(kong)制(zhi)(zhi)閥(fa)、速度(du)調(diao)節閥(fa)等。

電(dian)(dian)磁(ci)閥(fa)里有密閉的(de)(de)腔，在不(bu)同位置(zhi)開(kai)有通(tong)(tong)(tong)孔(kong)，每個孔(kong)連接不(bu)同的(de)(de)油管，腔中(zhong)間是活(huo)塞(sai)，兩面是兩塊電(dian)(dian)磁(ci)鐵，哪面的(de)(de)磁(ci)鐵線圈通(tong)(tong)(tong)電(dian)(dian)閥(fa)體(ti)(ti)就(jiu)會被吸引(yin)到(dao)哪邊(bian)，通(tong)(tong)(tong)過(guo)控(kong)制閥(fa)體(ti)(ti)的(de)(de)移動來(lai)開(kai)啟或關閉不(bu)同的(de)(de)排油孔(kong)，而進油孔(kong)是常(chang)開(kai)的(de)(de)，液(ye)壓油就(jiu)會進入(ru)不(bu)同的(de)(de)排油管，然(ran)后通(tong)(tong)(tong)過(guo)油的(de)(de)壓力來(lai)推(tui)動油缸的(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又(you)帶動活(huo)塞(sai)桿(gan)，活(huo)塞(sai)桿(gan)帶動機械(xie)裝置(zhi)。這樣通(tong)(tong)(tong)過(guo)控(kong)制電(dian)(dian)磁(ci)鐵的(de)(de)電(dian)(dian)流(liu)通(tong)(tong)(tong)斷就(jiu)控(kong)制了機械(xie)運動。

1、電磁閥從原理(li)上分為三大類：

直動(dong)式電(dian)磁(ci)閥

原(yuan)理(li)：通電(dian)(dian)(dian)(dian)時，電(dian)(dian)(dian)(dian)磁(ci)線圈產生電(dian)(dian)(dian)(dian)磁(ci)力(li)把關(guan)閉件從閥座上(shang)提起，閥門(men)打開；斷電(dian)(dian)(dian)(dian)時，電(dian)(dian)(dian)(dian)磁(ci)力(li)消失，彈簧(huang)把關(guan)閉件壓在(zai)閥座上(shang)，閥門(men)關(guan)閉。

特點：在真空、負壓、零壓時(shi)能正常(chang)工(gong)作，但通(tong)徑一般不超過25mm。

分步直動式(shi)電磁閥

原理：它(ta)是(shi)一種直動和先(xian)導式相結合的(de)原理，當入(ru)口(kou)與出口(kou)沒(mei)有壓(ya)(ya)差(cha)時，通(tong)電(dian)后(hou)，電(dian)磁(ci)力直接把先(xian)導小(xiao)閥(fa)(fa)和主閥(fa)(fa)關(guan)(guan)閉件(jian)依次向上提起，閥(fa)(fa)門(men)打開。當入(ru)口(kou)與出口(kou)達到啟動壓(ya)(ya)差(cha)時，通(tong)電(dian)后(hou)，電(dian)磁(ci)力先(xian)導小(xiao)閥(fa)(fa)，主閥(fa)(fa)下(xia)腔壓(ya)(ya)力上升(sheng)，上腔壓(ya)(ya)力下(xia)降(jiang)，從而利用壓(ya)(ya)差(cha)把主閥(fa)(fa)向上推開；斷電(dian)時，先(xian)導閥(fa)(fa)利用彈簧(huang)力或介質壓(ya)(ya)力推動關(guan)(guan)閉件(jian)，向下(xia)移動，使閥(fa)(fa)門(men)關(guan)(guan)閉。

特點：在零壓差(cha)或真空、高壓時亦能可*動作，但(dan)功率較大，要求必須水平安裝。

先導(dao)式電磁(ci)閥

原理：通電(dian)時，電(dian)磁力(li)把(ba)先(xian)導(dao)孔打(da)開(kai)，上(shang)腔室壓(ya)力(li)迅速(su)下(xia)降，在關(guan)(guan) 閉件(jian)周圍(wei)(wei)形成上(shang)低下(xia)高的壓(ya)差(cha)，流體(ti)壓(ya)力(li)推動關(guan)(guan)閉件(jian)向(xiang)上(shang)移動，閥(fa)門(men)打(da)開(kai)；斷電(dian)時，彈簧(huang)力(li)把(ba)先(xian)導(dao)孔關(guan)(guan)閉，入口壓(ya)力(li)通過旁通孔迅速(su)腔室在關(guan)(guan)閥(fa)件(jian)周圍(wei)(wei)形成下(xia)低上(shang)高的壓(ya)差(cha)，流體(ti)壓(ya)力(li)推動關(guan)(guan)閉件(jian)向(xiang)下(xia)移動，關(guan)(guan)閉閥(fa)門(men)。

特點：流體壓力范圍上限較(jiao)高，可任意安裝（需定(ding)制）但(dan)必須滿足流體壓差條件。

2、電磁(ci)閥從閥結(jie)構(gou)(gou)(gou)和材料上(shang)的不同與原理上(shang)的區別，分為(wei)六個分支小(xiao)類：直(zhi)動(dong)膜片(pian)結(jie)構(gou)(gou)(gou)、分步直(zhi)動(dong)膜片(pian)結(jie)構(gou)(gou)(gou)、先(xian)(xian)導膜片(pian)結(jie)構(gou)(gou)(gou)、直(zhi)動(dong)活(huo)塞結(jie)構(gou)(gou)(gou)、分步直(zhi)動(dong)活(huo)塞結(jie)構(gou)(gou)(gou)、先(xian)(xian)導活(huo)塞結(jie)構(gou)(gou)(gou)。

3、電(dian)(dian)磁(ci)(ci)(ci)閥(fa)按照(zhao)功能分(fen)類(lei)：水(shui)用電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、蒸汽電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、制冷(leng)電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、低溫電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、燃氣電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、消防電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、氨用電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、氣體電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、液(ye)體電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、微型(xing)電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、脈沖電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、液(ye)壓電(dian)(dian)磁(ci)(ci)(ci)閥(fa) 常開電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、油用電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、直流電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、高壓電(dian)(dian)磁(ci)(ci)(ci)閥(fa)、防爆(bao)電(dian)(dian)磁(ci)(ci)(ci)閥(fa)等。