電(dian)磁閥(fa)(fa)(fa)(fa)(fa)（Electromagnetic valve）是用電(dian)磁控(kong)(kong)制(zhi)(zhi)的(de)工(gong)業(ye)(ye)設(she)備(bei)，是用來(lai)控(kong)(kong)制(zhi)(zhi)流體(ti)的(de)自動化基礎元件，屬于執行器，并不限于液壓、氣動。用在工(gong)業(ye)(ye)控(kong)(kong)制(zhi)(zhi)系統中調整介質(zhi)的(de)方向、流量、速度和(he)其他的(de)參數。電(dian)磁閥(fa)(fa)(fa)(fa)(fa)可以(yi)配合不同的(de)電(dian)路來(lai)實(shi)現預期的(de)控(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)的(de)精(jing)度和(he)靈活性(xing)都(dou)能夠保證。電(dian)磁閥(fa)(fa)(fa)(fa)(fa)有很多種，不同的(de)電(dian)磁閥(fa)(fa)(fa)(fa)(fa)在控(kong)(kong)制(zhi)(zhi)系統的(de)不同位置發揮作用，最常用的(de)是單向閥(fa)(fa)(fa)(fa)(fa)、安全閥(fa)(fa)(fa)(fa)(fa)、方向控(kong)(kong)制(zhi)(zhi)閥(fa)(fa)(fa)(fa)(fa)、速度調節閥(fa)(fa)(fa)(fa)(fa)等。

電磁(ci)閥(fa)里有(you)密(mi)閉(bi)的(de)(de)(de)腔，在不(bu)同(tong)位(wei)置開(kai)有(you)通孔(kong)(kong)，每個(ge)孔(kong)(kong)連接不(bu)同(tong)的(de)(de)(de)油(you)管，腔中間是活塞(sai)，兩(liang)面是兩(liang)塊電磁(ci)鐵(tie)，哪面的(de)(de)(de)磁(ci)鐵(tie)線圈(quan)通電閥(fa)體就會(hui)被(bei)吸引到哪邊，通過(guo)控(kong)(kong)制閥(fa)體的(de)(de)(de)移動(dong)來(lai)開(kai)啟(qi)或(huo)關閉(bi)不(bu)同(tong)的(de)(de)(de)排(pai)油(you)孔(kong)(kong)，而進油(you)孔(kong)(kong)是常開(kai)的(de)(de)(de)，液壓(ya)油(you)就會(hui)進入(ru)不(bu)同(tong)的(de)(de)(de)排(pai)油(you)管，然(ran)后通過(guo)油(you)的(de)(de)(de)壓(ya)力來(lai)推動(dong)油(you)缸的(de)(de)(de)活塞(sai)，活塞(sai)又(you)帶動(dong)活塞(sai)桿，活塞(sai)桿帶動(dong)機械(xie)裝置。這樣通過(guo)控(kong)(kong)制電磁(ci)鐵(tie)的(de)(de)(de)電流通斷就控(kong)(kong)制了機械(xie)運(yun)動(dong)。

1、電(dian)磁閥從原理上分為三(san)大類：

直動式(shi)電磁閥

原理：通電(dian)時，電(dian)磁線圈產生電(dian)磁力(li)把關閉(bi)件從閥座上(shang)提起，閥門(men)打開；斷電(dian)時，電(dian)磁力(li)消失，彈簧把關閉(bi)件壓(ya)在閥座上(shang)，閥門(men)關閉(bi)。

特點：在真空(kong)、負壓、零(ling)壓時能正常工作，但通徑(jing)一(yi)般不超過25mm。

分步(bu)直動式(shi)電磁閥

原(yuan)理：它是一種(zhong)直動(dong)(dong)和先導式相結合(he)的原(yuan)理，當入口(kou)(kou)與(yu)出口(kou)(kou)沒有壓差時，通電(dian)后(hou)，電(dian)磁(ci)力(li)直接把先導小(xiao)閥(fa)和主閥(fa)關閉件依次向上(shang)(shang)提起，閥(fa)門打開。當入口(kou)(kou)與(yu)出口(kou)(kou)達到啟動(dong)(dong)壓差時，通電(dian)后(hou)，電(dian)磁(ci)力(li)先導小(xiao)閥(fa)，主閥(fa)下(xia)(xia)腔壓力(li)上(shang)(shang)升，上(shang)(shang)腔壓力(li)下(xia)(xia)降，從而利用壓差把主閥(fa)向上(shang)(shang)推(tui)開；斷電(dian)時，先導閥(fa)利用彈(dan)簧力(li)或(huo)介質壓力(li)推(tui)動(dong)(dong)關閉件，向下(xia)(xia)移動(dong)(dong)，使(shi)閥(fa)門關閉。

特點：在零壓差或真空、高壓時(shi)亦(yi)能可*動作，但功率(lv)較大，要求必須水平安裝。

先(xian)導式電磁閥

原(yuan)理：通電時，電磁力把先導(dao)孔打開(kai)(kai)，上腔室(shi)壓(ya)力迅(xun)速下(xia)(xia)降，在關(guan) 閉(bi)(bi)(bi)件(jian)周(zhou)圍(wei)形成(cheng)上低(di)下(xia)(xia)高(gao)的(de)壓(ya)差(cha)(cha)，流體壓(ya)力推動關(guan)閉(bi)(bi)(bi)件(jian)向上移(yi)動，閥門打開(kai)(kai)；斷電時，彈簧力把先導(dao)孔關(guan)閉(bi)(bi)(bi)，入口壓(ya)力通過旁通孔迅(xun)速腔室(shi)在關(guan)閥件(jian)周(zhou)圍(wei)形成(cheng)下(xia)(xia)低(di)上高(gao)的(de)壓(ya)差(cha)(cha)，流體壓(ya)力推動關(guan)閉(bi)(bi)(bi)件(jian)向下(xia)(xia)移(yi)動，關(guan)閉(bi)(bi)(bi)閥門。

特點：流體(ti)壓力范圍上(shang)限(xian)較高，可任意安裝(zhuang)（需定制）但必須滿(man)足(zu)流體(ti)壓差(cha)條件(jian)。

2、電磁閥(fa)從閥(fa)結(jie)(jie)構(gou)(gou)(gou)和材料(liao)上的(de)不同與原理上的(de)區別，分為六個分支小類：直(zhi)動(dong)膜(mo)片結(jie)(jie)構(gou)(gou)(gou)、分步(bu)直(zhi)動(dong)膜(mo)片結(jie)(jie)構(gou)(gou)(gou)、先導膜(mo)片結(jie)(jie)構(gou)(gou)(gou)、直(zhi)動(dong)活塞結(jie)(jie)構(gou)(gou)(gou)、分步(bu)直(zhi)動(dong)活塞結(jie)(jie)構(gou)(gou)(gou)、先導活塞結(jie)(jie)構(gou)(gou)(gou)。

3、電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)按照功(gong)能分類：水用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、燃氣(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氨用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、氣(qi)(qi)體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、脈(mo)沖(chong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、油用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、直(zhi)流電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)(fa)(fa)等。