電(dian)磁(ci)閥(fa)（Electromagnetic valve）是用(yong)電(dian)磁(ci)控(kong)(kong)制(zhi)(zhi)的(de)(de)(de)(de)(de)工業(ye)設備，是用(yong)來控(kong)(kong)制(zhi)(zhi)流體的(de)(de)(de)(de)(de)自動化基礎元件，屬于(yu)執行(xing)器，并不限(xian)于(yu)液(ye)壓、氣(qi)動。用(yong)在工業(ye)控(kong)(kong)制(zhi)(zhi)系(xi)(xi)統中調整介(jie)質的(de)(de)(de)(de)(de)方向(xiang)(xiang)、流量、速度和(he)其(qi)他(ta)的(de)(de)(de)(de)(de)參數(shu)。電(dian)磁(ci)閥(fa)可以配合不同的(de)(de)(de)(de)(de)電(dian)路來實現預期(qi)的(de)(de)(de)(de)(de)控(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)制(zhi)(zhi)的(de)(de)(de)(de)(de)精度和(he)靈活性都(dou)能夠保(bao)證。電(dian)磁(ci)閥(fa)有很多種，不同的(de)(de)(de)(de)(de)電(dian)磁(ci)閥(fa)在控(kong)(kong)制(zhi)(zhi)系(xi)(xi)統的(de)(de)(de)(de)(de)不同位置發揮(hui)作用(yong)，最(zui)常用(yong)的(de)(de)(de)(de)(de)是單向(xiang)(xiang)閥(fa)、安(an)全閥(fa)、方向(xiang)(xiang)控(kong)(kong)制(zhi)(zhi)閥(fa)、速度調節閥(fa)等。

電磁(ci)(ci)閥(fa)里有密閉(bi)的(de)(de)腔(qiang)，在不(bu)同(tong)位(wei)置開有通(tong)孔(kong)(kong)，每個孔(kong)(kong)連接不(bu)同(tong)的(de)(de)油(you)(you)管，腔(qiang)中間是(shi)(shi)活塞(sai)，兩(liang)(liang)面是(shi)(shi)兩(liang)(liang)塊電磁(ci)(ci)鐵(tie)，哪面的(de)(de)磁(ci)(ci)鐵(tie)線圈(quan)通(tong)電閥(fa)體就會被(bei)吸引到哪邊(bian)，通(tong)過(guo)(guo)控(kong)制(zhi)閥(fa)體的(de)(de)移動(dong)(dong)來開啟或關(guan)閉(bi)不(bu)同(tong)的(de)(de)排油(you)(you)孔(kong)(kong)，而進油(you)(you)孔(kong)(kong)是(shi)(shi)常(chang)開的(de)(de)，液壓油(you)(you)就會進入(ru)不(bu)同(tong)的(de)(de)排油(you)(you)管，然后通(tong)過(guo)(guo)油(you)(you)的(de)(de)壓力來推(tui)動(dong)(dong)油(you)(you)缸(gang)的(de)(de)活塞(sai)，活塞(sai)又(you)帶動(dong)(dong)活塞(sai)桿，活塞(sai)桿帶動(dong)(dong)機(ji)械裝置。這樣通(tong)過(guo)(guo)控(kong)制(zhi)電磁(ci)(ci)鐵(tie)的(de)(de)電流通(tong)斷就控(kong)制(zhi)了機(ji)械運動(dong)(dong)。

1、電磁閥從原理上(shang)分為三大類：

直動(dong)式電磁閥

原理：通電(dian)時，電(dian)磁線圈產生電(dian)磁力把關閉(bi)件從(cong)閥(fa)(fa)座(zuo)上提起(qi)，閥(fa)(fa)門打開；斷電(dian)時，電(dian)磁力消失(shi)，彈簧(huang)把關閉(bi)件壓在閥(fa)(fa)座(zuo)上，閥(fa)(fa)門關閉(bi)。

特點：在真空、負壓(ya)、零壓(ya)時能正常工作，但通徑(jing)一般不(bu)超過25mm。

分步直動式電磁閥

原理：它是一(yi)種直(zhi)動和先(xian)導式相結合的(de)原理，當入口(kou)與出口(kou)沒有壓(ya)(ya)差(cha)時，通電(dian)(dian)(dian)后(hou)，電(dian)(dian)(dian)磁力(li)直(zhi)接把先(xian)導小(xiao)閥(fa)(fa)和主(zhu)閥(fa)(fa)關(guan)(guan)閉件(jian)依次向(xiang)(xiang)上提(ti)起，閥(fa)(fa)門(men)打開。當入口(kou)與出口(kou)達到(dao)啟動壓(ya)(ya)差(cha)時，通電(dian)(dian)(dian)后(hou)，電(dian)(dian)(dian)磁力(li)先(xian)導小(xiao)閥(fa)(fa)，主(zhu)閥(fa)(fa)下(xia)腔壓(ya)(ya)力(li)上升，上腔壓(ya)(ya)力(li)下(xia)降，從而利用(yong)壓(ya)(ya)差(cha)把主(zhu)閥(fa)(fa)向(xiang)(xiang)上推開；斷電(dian)(dian)(dian)時，先(xian)導閥(fa)(fa)利用(yong)彈簧力(li)或介質壓(ya)(ya)力(li)推動關(guan)(guan)閉件(jian)，向(xiang)(xiang)下(xia)移動，使閥(fa)(fa)門(men)關(guan)(guan)閉。

特(te)點(dian)：在(zai)零壓差或(huo)真(zhen)空、高壓時亦能可*動作，但(dan)功率(lv)較(jiao)大(da)，要(yao)求必須水平安裝。

先導式電磁閥

原理(li)：通(tong)(tong)電時(shi)，電磁力把先導孔(kong)打(da)開，上(shang)腔(qiang)室壓(ya)(ya)力迅(xun)速(su)下降，在(zai)關(guan) 閉件(jian)周(zhou)圍形(xing)(xing)成(cheng)上(shang)低(di)下高的(de)壓(ya)(ya)差，流體(ti)壓(ya)(ya)力推動關(guan)閉件(jian)向上(shang)移(yi)動，閥門打(da)開；斷電時(shi)，彈簧力把先導孔(kong)關(guan)閉，入口壓(ya)(ya)力通(tong)(tong)過旁(pang)通(tong)(tong)孔(kong)迅(xun)速(su)腔(qiang)室在(zai)關(guan)閥件(jian)周(zhou)圍形(xing)(xing)成(cheng)下低(di)上(shang)高的(de)壓(ya)(ya)差，流體(ti)壓(ya)(ya)力推動關(guan)閉件(jian)向下移(yi)動，關(guan)閉閥門。

特點：流體(ti)壓力(li)范(fan)圍上限較高，可任意安裝(zhuang)（需定制）但必須滿足(zu)流體(ti)壓差條件。

2、電磁閥從閥結(jie)構(gou)(gou)(gou)和(he)材(cai)料上的不(bu)同與(yu)原理(li)上的區別(bie)，分(fen)為六個分(fen)支小類：直(zhi)(zhi)動(dong)(dong)膜(mo)(mo)(mo)片(pian)結(jie)構(gou)(gou)(gou)、分(fen)步(bu)直(zhi)(zhi)動(dong)(dong)膜(mo)(mo)(mo)片(pian)結(jie)構(gou)(gou)(gou)、先(xian)導膜(mo)(mo)(mo)片(pian)結(jie)構(gou)(gou)(gou)、直(zhi)(zhi)動(dong)(dong)活(huo)塞(sai)結(jie)構(gou)(gou)(gou)、分(fen)步(bu)直(zhi)(zhi)動(dong)(dong)活(huo)塞(sai)結(jie)構(gou)(gou)(gou)、先(xian)導活(huo)塞(sai)結(jie)構(gou)(gou)(gou)。

3、電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥按照功能分類：水用(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、蒸(zheng)汽(qi)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、制冷電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、低(di)溫電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、燃氣電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、消(xiao)防(fang)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、氨用(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、氣體電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、液體電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、微型電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、脈(mo)沖電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、液壓電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥 常開電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、油用(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、直流電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、高壓電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥、防(fang)爆電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥等。