電磁閥里有密閉的(de)腔，在(zai)不(bu)同位置(zhi)開有通(tong)(tong)(tong)(tong)孔(kong)(kong)，每(mei)個孔(kong)(kong)連接不(bu)同的(de)油(you)(you)(you)管，腔中間是(shi)活(huo)塞(sai)，兩面是(shi)兩塊電磁鐵，哪(na)面的(de)磁鐵線圈通(tong)(tong)(tong)(tong)電 閥體就(jiu)會被吸引到哪(na)邊(bian)，通(tong)(tong)(tong)(tong)過(guo)(guo)控制閥體的(de)移動(dong)來開啟或關閉不(bu)同的(de)排油(you)(you)(you)孔(kong)(kong)，而(er)進油(you)(you)(you)孔(kong)(kong)是(shi)常開的(de)，液(ye)壓(ya)(ya)油(you)(you)(you)就(jiu)會進入不(bu)同的(de)排油(you)(you)(you)管，然后 通(tong)(tong)(tong)(tong)過(guo)(guo)油(you)(you)(you)的(de)壓(ya)(ya)力來推(tui)動(dong)油(you)(you)(you)缸的(de)活(huo)塞(sai)，活(huo)塞(sai)又帶動(dong)活(huo)塞(sai)桿，活(huo)塞(sai)桿帶動(dong)機械裝置(zhi)。這樣通(tong)(tong)(tong)(tong)過(guo)(guo)控制電磁鐵的(de)電流通(tong)(tong)(tong)(tong)斷就(jiu)控制了機械運動(dong)。