電磁(ci)閥(fa)（Electromagnetic valve）是(shi)用電磁(ci)控(kong)(kong)制(zhi)的(de)(de)(de)(de)工(gong)業設備(bei)，是(shi)用來控(kong)(kong)制(zhi)流體的(de)(de)(de)(de)自動化基礎元(yuan)件，屬于執行器，并不(bu)(bu)限(xian)于液壓、氣動。用在工(gong)業控(kong)(kong)制(zhi)系(xi)統中調整介質的(de)(de)(de)(de)方向、流量(liang)、速度(du)和其他的(de)(de)(de)(de)參數。電磁(ci)閥(fa)可以配(pei)合(he)不(bu)(bu)同的(de)(de)(de)(de)電路來實現(xian)預期(qi)的(de)(de)(de)(de)控(kong)(kong)制(zhi)，而控(kong)(kong)制(zhi)的(de)(de)(de)(de)精度(du)和靈活性都能夠保證。電磁(ci)閥(fa)有很多種，不(bu)(bu)同的(de)(de)(de)(de)電磁(ci)閥(fa)在控(kong)(kong)制(zhi)系(xi)統的(de)(de)(de)(de)不(bu)(bu)同位(wei)置發揮(hui)作(zuo)用，最常(chang)用的(de)(de)(de)(de)是(shi)單向閥(fa)、安全(quan)閥(fa)、方向控(kong)(kong)制(zhi)閥(fa)、速度(du)調節閥(fa)等(deng)。

電(dian)磁閥里(li)有(you)密閉的(de)(de)腔(qiang)，在不(bu)同位置開有(you)通(tong)孔(kong)(kong)，每個孔(kong)(kong)連接不(bu)同的(de)(de)油(you)(you)管，腔(qiang)中間是活(huo)塞(sai)，兩面是兩塊電(dian)磁鐵(tie)，哪面的(de)(de)磁鐵(tie)線圈通(tong)電(dian)閥體就(jiu)會(hui)被(bei)吸引(yin)到哪邊，通(tong)過控制閥體的(de)(de)移動(dong)(dong)來開啟或關閉不(bu)同的(de)(de)排油(you)(you)孔(kong)(kong)，而(er)進(jin)(jin)油(you)(you)孔(kong)(kong)是常開的(de)(de)，液壓(ya)油(you)(you)就(jiu)會(hui)進(jin)(jin)入不(bu)同的(de)(de)排油(you)(you)管，然后通(tong)過油(you)(you)的(de)(de)壓(ya)力來推(tui)動(dong)(dong)油(you)(you)缸的(de)(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動(dong)(dong)活(huo)塞(sai)桿，活(huo)塞(sai)桿帶動(dong)(dong)機械(xie)裝置。這樣通(tong)過控制電(dian)磁鐵(tie)的(de)(de)電(dian)流通(tong)斷就(jiu)控制了機械(xie)運(yun)動(dong)(dong)。

1、電(dian)磁閥從(cong)原理上分為三(san)大類：

直動式(shi)電磁閥

原理：通(tong)電時(shi)，電磁線(xian)圈產(chan)生電磁力把關(guan)閉(bi)(bi)件(jian)從閥(fa)(fa)座(zuo)上(shang)提起，閥(fa)(fa)門打(da)開；斷電時(shi)，電磁力消失(shi)，彈簧把關(guan)閉(bi)(bi)件(jian)壓在(zai)閥(fa)(fa)座(zuo)上(shang)，閥(fa)(fa)門關(guan)閉(bi)(bi)。

特點：在真(zhen)空、負壓(ya)、零(ling)壓(ya)時能正(zheng)常工(gong)作(zuo)，但通(tong)徑一般不超過(guo)25mm。

分步(bu)直動式電磁閥

原(yuan)理(li)：它是一種(zhong)直動和先導式相(xiang)結合的原(yuan)理(li)，當入(ru)口與出口沒有壓(ya)(ya)差(cha)時，通(tong)電(dian)后，電(dian)磁力直接把先導小閥和主閥關(guan)(guan)閉件依次(ci)向上(shang)提起，閥門打開。當入(ru)口與出口達(da)到啟動壓(ya)(ya)差(cha)時，通(tong)電(dian)后，電(dian)磁力先導小閥，主閥下腔壓(ya)(ya)力上(shang)升，上(shang)腔壓(ya)(ya)力下降，從而(er)利用壓(ya)(ya)差(cha)把主閥向上(shang)推(tui)開；斷電(dian)時，先導閥利用彈簧(huang)力或介(jie)質(zhi)壓(ya)(ya)力推(tui)動關(guan)(guan)閉件，向下移動，使(shi)閥門關(guan)(guan)閉。

特點：在零壓差或真空、高(gao)壓時亦(yi)能可(ke)*動(dong)作(zuo)，但(dan)功率較大，要求必須水平安(an)裝。

先(xian)導式電磁閥

原理：通(tong)(tong)電時，電磁力(li)把先(xian)導(dao)孔打開(kai)，上(shang)腔室(shi)壓(ya)力(li)迅速(su)下降，在關(guan)(guan) 閉(bi)件周圍(wei)形成上(shang)低(di)下高的壓(ya)差，流(liu)體(ti)壓(ya)力(li)推(tui)(tui)動(dong)(dong)關(guan)(guan)閉(bi)件向上(shang)移動(dong)(dong)，閥門(men)打開(kai)；斷電時，彈簧力(li)把先(xian)導(dao)孔關(guan)(guan)閉(bi)，入口壓(ya)力(li)通(tong)(tong)過(guo)旁通(tong)(tong)孔迅速(su)腔室(shi)在關(guan)(guan)閥件周圍(wei)形成下低(di)上(shang)高的壓(ya)差，流(liu)體(ti)壓(ya)力(li)推(tui)(tui)動(dong)(dong)關(guan)(guan)閉(bi)件向下移動(dong)(dong)，關(guan)(guan)閉(bi)閥門(men)。

特(te)點：流(liu)體壓力范(fan)圍上限較高，可任意安裝（需定制）但必須滿足流(liu)體壓差條(tiao)件(jian)。

2、電磁閥從閥結(jie)(jie)(jie)構和材料(liao)上(shang)的不(bu)同與(yu)原理上(shang)的區別，分為六個分支(zhi)小類：直(zhi)動(dong)(dong)膜(mo)片結(jie)(jie)(jie)構、分步直(zhi)動(dong)(dong)膜(mo)片結(jie)(jie)(jie)構、先導膜(mo)片結(jie)(jie)(jie)構、直(zhi)動(dong)(dong)活(huo)塞(sai)結(jie)(jie)(jie)構、分步直(zhi)動(dong)(dong)活(huo)塞(sai)結(jie)(jie)(jie)構、先導活(huo)塞(sai)結(jie)(jie)(jie)構。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)按(an)照功能分類：水用(yong)(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、蒸(zheng)汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、制(zhi)冷(leng)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、低溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氨(an)用(yong)(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、微(wei)型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、脈(mo)沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、液壓(ya)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、油(you)用(yong)(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、高壓(ya)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)等(deng)。