電(dian)(dian)磁閥(fa)(fa)（Electromagnetic valve）是(shi)用(yong)(yong)電(dian)(dian)磁控(kong)(kong)制(zhi)(zhi)的(de)(de)工(gong)業設備，是(shi)用(yong)(yong)來控(kong)(kong)制(zhi)(zhi)流(liu)體的(de)(de)自(zi)動(dong)化基礎(chu)元件，屬于(yu)執行(xing)器，并不(bu)限于(yu)液壓、氣動(dong)。用(yong)(yong)在工(gong)業控(kong)(kong)制(zhi)(zhi)系統中(zhong)調整介質的(de)(de)方(fang)(fang)向(xiang)、流(liu)量、速度(du)和其他(ta)的(de)(de)參數。電(dian)(dian)磁閥(fa)(fa)可以配(pei)合不(bu)同(tong)的(de)(de)電(dian)(dian)路(lu)來實(shi)現預(yu)期的(de)(de)控(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)的(de)(de)精(jing)度(du)和靈(ling)活性(xing)都能夠保證。電(dian)(dian)磁閥(fa)(fa)有很多種，不(bu)同(tong)的(de)(de)電(dian)(dian)磁閥(fa)(fa)在控(kong)(kong)制(zhi)(zhi)系統的(de)(de)不(bu)同(tong)位置發揮作用(yong)(yong)，最常用(yong)(yong)的(de)(de)是(shi)單向(xiang)閥(fa)(fa)、安全閥(fa)(fa)、方(fang)(fang)向(xiang)控(kong)(kong)制(zhi)(zhi)閥(fa)(fa)、速度(du)調節閥(fa)(fa)等。

電磁(ci)閥(fa)(fa)里有密閉的腔，在(zai)不同(tong)位置開有通孔，每(mei)個孔連接(jie)不同(tong)的油(you)(you)管，腔中間是活(huo)(huo)塞(sai)(sai)(sai)，兩面是兩塊電磁(ci)鐵，哪面的磁(ci)鐵線圈通電閥(fa)(fa)體就(jiu)會被吸引到哪邊，通過(guo)控制閥(fa)(fa)體的移動(dong)來(lai)(lai)開啟或關(guan)閉不同(tong)的排油(you)(you)孔，而進油(you)(you)孔是常(chang)開的，液壓油(you)(you)就(jiu)會進入不同(tong)的排油(you)(you)管，然后通過(guo)油(you)(you)的壓力來(lai)(lai)推(tui)動(dong)油(you)(you)缸的活(huo)(huo)塞(sai)(sai)(sai)，活(huo)(huo)塞(sai)(sai)(sai)又(you)帶(dai)動(dong)活(huo)(huo)塞(sai)(sai)(sai)桿，活(huo)(huo)塞(sai)(sai)(sai)桿帶(dai)動(dong)機械裝置。這樣(yang)通過(guo)控制電磁(ci)鐵的電流(liu)通斷就(jiu)控制了機械運動(dong)。

1、電(dian)磁閥(fa)從原理上分為三大(da)類：

直動式(shi)電磁閥

原理：通(tong)電(dian)時，電(dian)磁(ci)(ci)線圈產(chan)生電(dian)磁(ci)(ci)力把(ba)關(guan)閉(bi)件(jian)從閥(fa)(fa)座(zuo)上(shang)提起(qi)，閥(fa)(fa)門(men)打開；斷電(dian)時，電(dian)磁(ci)(ci)力消失，彈簧(huang)把(ba)關(guan)閉(bi)件(jian)壓在閥(fa)(fa)座(zuo)上(shang)，閥(fa)(fa)門(men)關(guan)閉(bi)。

特點(dian)：在(zai)真空、負(fu)壓、零(ling)壓時能正(zheng)常工作，但(dan)通徑一般不(bu)超過(guo)25mm。

分步(bu)直動式(shi)電磁(ci)閥

原理：它(ta)是一種直動(dong)和先(xian)(xian)導(dao)式相結合(he)的原理，當入口與(yu)(yu)出(chu)口沒有壓(ya)(ya)差時(shi)，通(tong)電后，電磁(ci)力直接把(ba)先(xian)(xian)導(dao)小(xiao)閥和主(zhu)閥關閉(bi)(bi)件依次向上(shang)提(ti)起(qi)，閥門打開(kai)。當入口與(yu)(yu)出(chu)口達到啟動(dong)壓(ya)(ya)差時(shi)，通(tong)電后，電磁(ci)力先(xian)(xian)導(dao)小(xiao)閥，主(zhu)閥下(xia)腔壓(ya)(ya)力上(shang)升，上(shang)腔壓(ya)(ya)力下(xia)降，從而利用壓(ya)(ya)差把(ba)主(zhu)閥向上(shang)推開(kai)；斷電時(shi)，先(xian)(xian)導(dao)閥利用彈簧力或介質壓(ya)(ya)力推動(dong)關閉(bi)(bi)件，向下(xia)移動(dong)，使閥門關閉(bi)(bi)。

特點：在(zai)零壓差或真空、高(gao)壓時亦(yi)能可(ke)*動作，但功率較大，要求必須水平安裝(zhuang)。

先導式電磁(ci)閥

原理(li)：通(tong)(tong)電(dian)時，電(dian)磁力把(ba)先導(dao)孔(kong)(kong)打開(kai)，上(shang)(shang)腔室壓(ya)力迅(xun)速下降，在關(guan)(guan) 閉(bi)(bi)(bi)件(jian)周(zhou)(zhou)圍形(xing)成上(shang)(shang)低(di)下高(gao)的壓(ya)差，流體壓(ya)力推動(dong)關(guan)(guan)閉(bi)(bi)(bi)件(jian)向(xiang)上(shang)(shang)移動(dong)，閥(fa)門(men)打開(kai)；斷電(dian)時，彈簧力把(ba)先導(dao)孔(kong)(kong)關(guan)(guan)閉(bi)(bi)(bi)，入口壓(ya)力通(tong)(tong)過旁通(tong)(tong)孔(kong)(kong)迅(xun)速腔室在關(guan)(guan)閥(fa)件(jian)周(zhou)(zhou)圍形(xing)成下低(di)上(shang)(shang)高(gao)的壓(ya)差，流體壓(ya)力推動(dong)關(guan)(guan)閉(bi)(bi)(bi)件(jian)向(xiang)下移動(dong)，關(guan)(guan)閉(bi)(bi)(bi)閥(fa)門(men)。

特點：流體(ti)壓(ya)力范圍上限較高，可(ke)任意(yi)安裝(zhuang)（需定制）但(dan)必須(xu)滿足流體(ti)壓(ya)差條件。

2、電磁(ci)閥從閥結構(gou)和材料上(shang)的不同與(yu)原理(li)上(shang)的區別(bie)，分為六個分支(zhi)小(xiao)類：直動(dong)膜片(pian)(pian)結構(gou)、分步直動(dong)膜片(pian)(pian)結構(gou)、先導(dao)膜片(pian)(pian)結構(gou)、直動(dong)活塞(sai)結構(gou)、分步直動(dong)活塞(sai)結構(gou)、先導(dao)活塞(sai)結構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(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)閥(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、燃氣(qi)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、氣(qi)體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、微型(xing)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa) 常開(kai)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)等。