電(dian)磁(ci)(ci)(ci)(ci)閥（Electromagnetic valve）是(shi)用電(dian)磁(ci)(ci)(ci)(ci)控(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)工業(ye)設備，是(shi)用來控(kong)(kong)(kong)(kong)制(zhi)(zhi)流(liu)體(ti)的(de)(de)自動化基礎元件，屬(shu)于執行器，并不限于液壓、氣動。用在工業(ye)控(kong)(kong)(kong)(kong)制(zhi)(zhi)系統(tong)(tong)中調整介質的(de)(de)方向(xiang)、流(liu)量、速(su)度(du)和其他的(de)(de)參數。電(dian)磁(ci)(ci)(ci)(ci)閥可以配合不同的(de)(de)電(dian)路來實現預期的(de)(de)控(kong)(kong)(kong)(kong)制(zhi)(zhi)，而控(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)精度(du)和靈活(huo)性都能夠保(bao)證。電(dian)磁(ci)(ci)(ci)(ci)閥有(you)很多種，不同的(de)(de)電(dian)磁(ci)(ci)(ci)(ci)閥在控(kong)(kong)(kong)(kong)制(zhi)(zhi)系統(tong)(tong)的(de)(de)不同位置發揮(hui)作(zuo)用，最常用的(de)(de)是(shi)單向(xiang)閥、安全(quan)閥、方向(xiang)控(kong)(kong)(kong)(kong)制(zhi)(zhi)閥、速(su)度(du)調節閥等。

電磁(ci)(ci)閥(fa)里有(you)密閉的(de)(de)腔，在不同位置開有(you)通(tong)孔，每個孔連接(jie)不同的(de)(de)油管(guan)，腔中(zhong)間(jian)是(shi)(shi)(shi)活(huo)塞，兩面是(shi)(shi)(shi)兩塊電磁(ci)(ci)鐵，哪面的(de)(de)磁(ci)(ci)鐵線圈通(tong)電閥(fa)體就(jiu)(jiu)會被(bei)吸(xi)引(yin)到哪邊，通(tong)過(guo)控制(zhi)(zhi)閥(fa)體的(de)(de)移動(dong)來開啟(qi)或關閉不同的(de)(de)排油孔，而進油孔是(shi)(shi)(shi)常開的(de)(de)，液壓(ya)油就(jiu)(jiu)會進入不同的(de)(de)排油管(guan)，然(ran)后通(tong)過(guo)油的(de)(de)壓(ya)力來推動(dong)油缸的(de)(de)活(huo)塞，活(huo)塞又帶動(dong)活(huo)塞桿，活(huo)塞桿帶動(dong)機械裝置。這樣通(tong)過(guo)控制(zhi)(zhi)電磁(ci)(ci)鐵的(de)(de)電流通(tong)斷就(jiu)(jiu)控制(zhi)(zhi)了機械運(yun)動(dong)。

1、電(dian)磁(ci)閥從原理上分為(wei)三(san)大類：

直(zhi)動式電磁閥

原理：通電(dian)時，電(dian)磁(ci)線圈產生(sheng)電(dian)磁(ci)力把關(guan)閉件從閥(fa)(fa)座上提(ti)起(qi)，閥(fa)(fa)門打開；斷電(dian)時，電(dian)磁(ci)力消失，彈簧把關(guan)閉件壓在閥(fa)(fa)座上，閥(fa)(fa)門關(guan)閉。

特點：在真空、負壓(ya)、零(ling)壓(ya)時能正常工作，但通徑一般不超過25mm。

分步直動式電磁閥

原理(li)：它是一種直(zhi)動和(he)先導(dao)式相(xiang)結(jie)合的原理(li)，當(dang)入口(kou)與出口(kou)沒有壓差時，通電(dian)(dian)后，電(dian)(dian)磁(ci)力直(zhi)接把(ba)先導(dao)小閥(fa)(fa)和(he)主閥(fa)(fa)關(guan)(guan)閉(bi)件(jian)依次向上(shang)提起(qi)，閥(fa)(fa)門打開。當(dang)入口(kou)與出口(kou)達到啟動壓差時，通電(dian)(dian)后，電(dian)(dian)磁(ci)力先導(dao)小閥(fa)(fa)，主閥(fa)(fa)下(xia)腔壓力上(shang)升，上(shang)腔壓力下(xia)降，從而利(li)用壓差把(ba)主閥(fa)(fa)向上(shang)推(tui)開；斷電(dian)(dian)時，先導(dao)閥(fa)(fa)利(li)用彈(dan)簧力或(huo)介(jie)質壓力推(tui)動關(guan)(guan)閉(bi)件(jian)，向下(xia)移動，使(shi)閥(fa)(fa)門關(guan)(guan)閉(bi)。

特(te)點：在零壓(ya)差或真空、高壓(ya)時亦(yi)能可*動作(zuo)，但功率較大(da)，要(yao)求必須水(shui)平安(an)裝。

先導式電磁(ci)閥(fa)

原理：通電時，電磁力(li)把(ba)先導(dao)孔打(da)開(kai)，上腔室壓(ya)力(li)迅速下(xia)(xia)降(jiang)，在關(guan)(guan) 閉(bi)件(jian)周(zhou)圍(wei)形(xing)成(cheng)上低下(xia)(xia)高的壓(ya)差，流體壓(ya)力(li)推動關(guan)(guan)閉(bi)件(jian)向上移動，閥門打(da)開(kai)；斷電時，彈(dan)簧力(li)把(ba)先導(dao)孔關(guan)(guan)閉(bi)，入口壓(ya)力(li)通過旁通孔迅速腔室在關(guan)(guan)閥件(jian)周(zhou)圍(wei)形(xing)成(cheng)下(xia)(xia)低上高的壓(ya)差，流體壓(ya)力(li)推動關(guan)(guan)閉(bi)件(jian)向下(xia)(xia)移動，關(guan)(guan)閉(bi)閥門。

特點：流(liu)體壓(ya)力范圍上(shang)限(xian)較(jiao)高，可(ke)任(ren)意安裝（需定制）但必須滿足流(liu)體壓(ya)差(cha)條(tiao)件(jian)。

2、電磁閥從閥結構(gou)和材料上的不同與原理上的區別，分(fen)為六個分(fen)支(zhi)小(xiao)類(lei)：直動膜(mo)片(pian)(pian)結構(gou)、分(fen)步(bu)直動膜(mo)片(pian)(pian)結構(gou)、先導膜(mo)片(pian)(pian)結構(gou)、直動活(huo)塞(sai)結構(gou)、分(fen)步(bu)直動活(huo)塞(sai)結構(gou)、先導活(huo)塞(sai)結構(gou)。

3、電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)按照功能分(fen)類(lei)：水(shui)用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、制(zhi)冷電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、低溫電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、燃(ran)氣電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、消防電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、氨用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、氣體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、液體電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、微型電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、液壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa) 常開電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、油用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、直流電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、高(gao)壓電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)、防爆(bao)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)閥(fa)(fa)等(deng)。