電(dian)磁閥(fa)(fa)（Electromagnetic valve）是用(yong)電(dian)磁控制(zhi)的(de)工業(ye)設備，是用(yong)來控制(zhi)流體的(de)自動化基礎(chu)元件，屬于(yu)執(zhi)行器，并不(bu)(bu)限于(yu)液壓(ya)、氣動。用(yong)在(zai)工業(ye)控制(zhi)系統中(zhong)調(diao)整介質的(de)方向(xiang)、流量、速度和(he)其他的(de)參數(shu)。電(dian)磁閥(fa)(fa)可以配合不(bu)(bu)同的(de)電(dian)路來實現預期(qi)的(de)控制(zhi)，而控制(zhi)的(de)精度和(he)靈(ling)活性都(dou)能夠保證。電(dian)磁閥(fa)(fa)有很多(duo)種，不(bu)(bu)同的(de)電(dian)磁閥(fa)(fa)在(zai)控制(zhi)系統的(de)不(bu)(bu)同位置發揮作用(yong)，最常用(yong)的(de)是單向(xiang)閥(fa)(fa)、安全閥(fa)(fa)、方向(xiang)控制(zhi)閥(fa)(fa)、速度調(diao)節閥(fa)(fa)等。

電(dian)(dian)(dian)磁(ci)(ci)閥(fa)里有密閉(bi)的腔，在不(bu)(bu)同位(wei)置(zhi)開(kai)有通(tong)(tong)孔(kong)(kong)，每個孔(kong)(kong)連接(jie)不(bu)(bu)同的油(you)(you)管(guan)，腔中間是(shi)活塞(sai)(sai)，兩面是(shi)兩塊(kuai)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)，哪面的磁(ci)(ci)鐵(tie)(tie)線(xian)圈(quan)通(tong)(tong)電(dian)(dian)(dian)閥(fa)體就會被吸引(yin)到哪邊，通(tong)(tong)過控制閥(fa)體的移(yi)動來開(kai)啟或關閉(bi)不(bu)(bu)同的排油(you)(you)孔(kong)(kong)，而進(jin)油(you)(you)孔(kong)(kong)是(shi)常開(kai)的，液壓油(you)(you)就會進(jin)入不(bu)(bu)同的排油(you)(you)管(guan)，然(ran)后(hou)通(tong)(tong)過油(you)(you)的壓力來推動油(you)(you)缸的活塞(sai)(sai)，活塞(sai)(sai)又帶動活塞(sai)(sai)桿，活塞(sai)(sai)桿帶動機械(xie)裝置(zhi)。這樣(yang)通(tong)(tong)過控制電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)的電(dian)(dian)(dian)流通(tong)(tong)斷就控制了機械(xie)運(yun)動。

1、電磁閥從原理(li)上(shang)分為三大類：

直(zhi)動式(shi)電磁閥

原理：通電(dian)時，電(dian)磁(ci)線圈產生電(dian)磁(ci)力(li)把關閉(bi)件(jian)從閥座上(shang)提起(qi)，閥門打開；斷電(dian)時，電(dian)磁(ci)力(li)消失，彈簧把關閉(bi)件(jian)壓在閥座上(shang)，閥門關閉(bi)。

特點：在真(zhen)空、負壓、零壓時能正常工作，但通徑一般不(bu)超過25mm。

分步直動式電磁閥

原(yuan)理：它是一種直(zhi)動和先(xian)導式相結(jie)合的原(yuan)理，當(dang)入口與(yu)出口沒有壓(ya)差(cha)(cha)時(shi)，通電(dian)后(hou)，電(dian)磁力直(zhi)接把先(xian)導小閥和主(zhu)(zhu)閥關閉(bi)(bi)件(jian)依次向(xiang)上(shang)提起(qi)，閥門打開(kai)(kai)。當(dang)入口與(yu)出口達到啟動壓(ya)差(cha)(cha)時(shi)，通電(dian)后(hou)，電(dian)磁力先(xian)導小閥，主(zhu)(zhu)閥下腔壓(ya)力上(shang)升，上(shang)腔壓(ya)力下降，從而利用壓(ya)差(cha)(cha)把主(zhu)(zhu)閥向(xiang)上(shang)推(tui)開(kai)(kai)；斷電(dian)時(shi)，先(xian)導閥利用彈簧(huang)力或介質壓(ya)力推(tui)動關閉(bi)(bi)件(jian)，向(xiang)下移動，使閥門關閉(bi)(bi)。

特點：在(zai)零壓(ya)差(cha)或真(zhen)空、高壓(ya)時(shi)亦能可*動作，但功率較大(da)，要求必須水平安(an)裝。

先導式電磁閥

原理：通(tong)電(dian)時(shi)，電(dian)磁力把(ba)先導孔打開(kai)，上(shang)腔室壓(ya)力迅速下(xia)降，在關(guan) 閉(bi)件(jian)周(zhou)圍形成上(shang)低下(xia)高的壓(ya)差(cha)，流(liu)體壓(ya)力推動關(guan)閉(bi)件(jian)向上(shang)移(yi)動，閥(fa)門(men)(men)打開(kai)；斷(duan)電(dian)時(shi)，彈簧(huang)力把(ba)先導孔關(guan)閉(bi)，入口(kou)壓(ya)力通(tong)過旁通(tong)孔迅速腔室在關(guan)閥(fa)件(jian)周(zhou)圍形成下(xia)低上(shang)高的壓(ya)差(cha)，流(liu)體壓(ya)力推動關(guan)閉(bi)件(jian)向下(xia)移(yi)動，關(guan)閉(bi)閥(fa)門(men)(men)。

特點：流體壓力范圍上限較(jiao)高，可任意安裝（需定制）但必(bi)須滿(man)足(zu)流體壓差條件。

2、電磁閥從閥結構(gou)和(he)材料上的不同(tong)與原理上的區別，分為六個(ge)分支(zhi)小類：直(zhi)動(dong)膜(mo)片(pian)結構(gou)、分步(bu)直(zhi)動(dong)膜(mo)片(pian)結構(gou)、先導膜(mo)片(pian)結構(gou)、直(zhi)動(dong)活塞結構(gou)、分步(bu)直(zhi)動(dong)活塞結構(gou)、先導活塞結構(gou)。

3、電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)按(an)照功能分類：水(shui)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、蒸汽電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、制冷電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、低(di)溫電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、燃氣電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、消(xiao)防電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氨用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、氣體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)體電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、微型電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、脈沖電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、液(ye)壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa) 常開電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、油(you)用(yong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、直流電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、高壓電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)、防爆電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)閥(fa)(fa)(fa)(fa)等(deng)。