電(dian)磁(ci)閥(fa)(fa)（Electromagnetic valve）是(shi)用(yong)(yong)電(dian)磁(ci)控(kong)制(zhi)(zhi)的(de)工(gong)業(ye)設備，是(shi)用(yong)(yong)來控(kong)制(zhi)(zhi)流體的(de)自動(dong)(dong)化基(ji)礎元(yuan)件，屬于執(zhi)行器，并不(bu)限于液(ye)壓(ya)、氣動(dong)(dong)。用(yong)(yong)在工(gong)業(ye)控(kong)制(zhi)(zhi)系(xi)統中調整介質的(de)方向(xiang)、流量、速(su)(su)度和(he)其他的(de)參數。電(dian)磁(ci)閥(fa)(fa)可以配合(he)不(bu)同(tong)的(de)電(dian)路(lu)來實(shi)現預期的(de)控(kong)制(zhi)(zhi)，而控(kong)制(zhi)(zhi)的(de)精(jing)度和(he)靈活性都能夠保(bao)證。電(dian)磁(ci)閥(fa)(fa)有很多(duo)種，不(bu)同(tong)的(de)電(dian)磁(ci)閥(fa)(fa)在控(kong)制(zhi)(zhi)系(xi)統的(de)不(bu)同(tong)位置發揮作(zuo)用(yong)(yong)，最常用(yong)(yong)的(de)是(shi)單向(xiang)閥(fa)(fa)、安全(quan)閥(fa)(fa)、方向(xiang)控(kong)制(zhi)(zhi)閥(fa)(fa)、速(su)(su)度調節閥(fa)(fa)等(deng)。

電(dian)(dian)(dian)(dian)磁閥(fa)(fa)里有密(mi)閉(bi)的(de)腔，在不(bu)同位置開有通(tong)孔(kong)(kong)，每個孔(kong)(kong)連(lian)接(jie)不(bu)同的(de)油(you)(you)(you)(you)管，腔中間(jian)是(shi)活(huo)(huo)(huo)(huo)塞(sai)(sai)，兩(liang)(liang)面(mian)(mian)是(shi)兩(liang)(liang)塊(kuai)電(dian)(dian)(dian)(dian)磁鐵，哪面(mian)(mian)的(de)磁鐵線(xian)圈通(tong)電(dian)(dian)(dian)(dian)閥(fa)(fa)體就會被吸引到(dao)哪邊(bian)，通(tong)過控(kong)制(zhi)(zhi)閥(fa)(fa)體的(de)移動(dong)(dong)來開啟(qi)或關閉(bi)不(bu)同的(de)排油(you)(you)(you)(you)孔(kong)(kong)，而進(jin)油(you)(you)(you)(you)孔(kong)(kong)是(shi)常開的(de)，液壓油(you)(you)(you)(you)就會進(jin)入不(bu)同的(de)排油(you)(you)(you)(you)管，然后通(tong)過油(you)(you)(you)(you)的(de)壓力來推動(dong)(dong)油(you)(you)(you)(you)缸的(de)活(huo)(huo)(huo)(huo)塞(sai)(sai)，活(huo)(huo)(huo)(huo)塞(sai)(sai)又帶(dai)動(dong)(dong)活(huo)(huo)(huo)(huo)塞(sai)(sai)桿，活(huo)(huo)(huo)(huo)塞(sai)(sai)桿帶(dai)動(dong)(dong)機械裝(zhuang)置。這樣(yang)通(tong)過控(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)磁鐵的(de)電(dian)(dian)(dian)(dian)流通(tong)斷就控(kong)制(zhi)(zhi)了(le)機械運動(dong)(dong)。

1、電磁閥從(cong)原理上(shang)分為三大類：

直動(dong)式電磁(ci)閥

原理(li)：通電(dian)(dian)時，電(dian)(dian)磁(ci)線圈產生電(dian)(dian)磁(ci)力把關(guan)(guan)閉(bi)(bi)件從閥座上提起，閥門打開；斷電(dian)(dian)時，電(dian)(dian)磁(ci)力消(xiao)失，彈簧把關(guan)(guan)閉(bi)(bi)件壓在閥座上，閥門關(guan)(guan)閉(bi)(bi)。

特點：在(zai)真空、負壓、零壓時能正常工(gong)作，但通徑(jing)一般不超過25mm。

分步(bu)直動(dong)式電磁閥

原理：它是一種直動(dong)和(he)(he)先導式相結合的(de)原理，當(dang)入口(kou)與出(chu)口(kou)沒有壓差時，通電后，電磁(ci)力(li)(li)直接把(ba)先導小(xiao)閥(fa)和(he)(he)主閥(fa)關(guan)閉(bi)件(jian)依次向上提起，閥(fa)門(men)打(da)開。當(dang)入口(kou)與出(chu)口(kou)達到(dao)啟(qi)動(dong)壓差時，通電后，電磁(ci)力(li)(li)先導小(xiao)閥(fa)，主閥(fa)下腔壓力(li)(li)上升，上腔壓力(li)(li)下降，從而利用(yong)壓差把(ba)主閥(fa)向上推開；斷電時，先導閥(fa)利用(yong)彈(dan)簧力(li)(li)或介質壓力(li)(li)推動(dong)關(guan)閉(bi)件(jian)，向下移動(dong)，使閥(fa)門(men)關(guan)閉(bi)。

特點：在零(ling)壓差或真空、高壓時亦(yi)能可*動作，但功率較(jiao)大，要(yao)求必須水(shui)平(ping)安(an)裝(zhuang)。

先導式電磁閥

原理：通(tong)電(dian)(dian)時，電(dian)(dian)磁力把先(xian)導孔打(da)開，上腔(qiang)(qiang)室(shi)壓(ya)(ya)力迅速下降，在(zai)關(guan) 閉件(jian)周(zhou)圍形成上低(di)下高(gao)的(de)壓(ya)(ya)差(cha)，流(liu)體壓(ya)(ya)力推(tui)動(dong)(dong)關(guan)閉件(jian)向(xiang)上移動(dong)(dong)，閥門(men)打(da)開；斷電(dian)(dian)時，彈簧力把先(xian)導孔關(guan)閉，入口壓(ya)(ya)力通(tong)過旁(pang)通(tong)孔迅速腔(qiang)(qiang)室(shi)在(zai)關(guan)閥件(jian)周(zhou)圍形成下低(di)上高(gao)的(de)壓(ya)(ya)差(cha)，流(liu)體壓(ya)(ya)力推(tui)動(dong)(dong)關(guan)閉件(jian)向(xiang)下移動(dong)(dong)，關(guan)閉閥門(men)。

特點：流(liu)體壓力范圍(wei)上限較高，可任(ren)意(yi)安(an)裝（需(xu)定制(zhi)）但必(bi)須滿足流(liu)體壓差條(tiao)件。

2、電磁閥從閥結(jie)構(gou)和材料上的(de)不同(tong)與原理上的(de)區別，分(fen)為六(liu)個分(fen)支小類：直動(dong)膜(mo)片結(jie)構(gou)、分(fen)步(bu)直動(dong)膜(mo)片結(jie)構(gou)、先(xian)(xian)導(dao)膜(mo)片結(jie)構(gou)、直動(dong)活塞結(jie)構(gou)、分(fen)步(bu)直動(dong)活塞結(jie)構(gou)、先(xian)(xian)導(dao)活塞結(jie)構(gou)。

3、電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)按(an)照功能分類：水(shui)用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷(leng)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、低(di)溫電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣(qi)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、消防電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、氣(qi)體(ti)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)體(ti)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa) 常(chang)開電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、油用(yong)電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)磁(ci)(ci)閥(fa)(fa)(fa)(fa)等。