電磁鐵的發明

1822年，法國物理學家阿拉戈和呂薩克發現，當電流通過其中有鐵塊的繞線時，它能使繞線中的鐵塊磁化。這實際上是惠州電磁鐵原理的最初發現。1823年，斯特金(jin)也做了一(yi)次類似的實驗(yan)：他在一(yi)根并(bing)非是磁(ci)鐵(tie)(tie)(tie)(tie)棒的U型(xing)(xing)鐵(tie)(tie)(tie)(tie)棒上(shang)繞了18圈銅裸線，當銅線與伏打電池接(jie)通時，繞在U型(xing)(xing)鐵(tie)(tie)(tie)(tie)棒上(shang)的銅線圈即產生了密集(ji)的磁(ci)場，這樣(yang)就使U型(xing)(xing)鐵(tie)(tie)(tie)(tie)棒變成了一(yi)塊(kuai)(kuai)“電磁(ci)鐵(tie)(tie)(tie)(tie)”。這種電磁(ci)鐵(tie)(tie)(tie)(tie)上(shang)的磁(ci)能要比永磁(ci)能大放(fang)多倍，它(ta)(ta)能吸起(qi)比它(ta)(ta)重20倍的鐵(tie)(tie)(tie)(tie)塊(kuai)(kuai)，而當電源(yuan)切斷后(hou)，U型(xing)(xing)鐵(tie)(tie)(tie)(tie)棒就什(shen)么(me)鐵(tie)(tie)(tie)(tie)塊(kuai)(kuai)也吸不住(zhu)，重新成為一(yi)根普通的鐵(tie)(tie)(tie)(tie)棒。

斯特金的(de)(de)電磁鐵發明(ming)，使人們(men)看到了(le)把電能(neng)轉(zhuan)化(hua)為磁能(neng)的(de)(de)光(guang)明(ming)前景，這一發明(ming)很快在英國、美國以及(ji)西(xi)歐(ou)一些(xie)沿海國家(jia)傳播(bo)開(kai)來。

1829年(nian)，美國電學家亨(heng)(heng)利對(dui)斯(si)特(te)金(jin)電磁(ci)鐵裝置進行(xing)了一(yi)些革新(xin)，絕緣導線(xian)代替裸銅導線(xian)，因此不必擔心被(bei)銅導線(xian)過分靠近(jin)而(er)短(duan)路。由(you)于(yu)導線(xian)有了絕緣層(ceng)，就(jiu)可以將它(ta)們(men)一(yi)圈(quan)圈(quan)地緊緊地繞在(zai)一(yi)起(qi)，由(you)于(yu)線(xian)圈(quan)越密集，產生(sheng)的(de)磁(ci)場就(jiu)越強，這樣就(jiu)大(da)大(da)提高了把電能轉化為磁(ci)能的(de)能力(li)。到了1831年(nian)，亨(heng)(heng)利試制出(chu)了一(yi)塊更新(xin)的(de)電磁(ci)鐵，雖然它(ta)的(de)體積并(bing)不大(da)，但它(ta)能吸起(qi)1噸重的(de)鐵塊。

電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)內部帶(dai)有(you)(you)鐵(tie)(tie)心的(de)(de)(de)、利用(yong)通(tong)有(you)(you)電(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)線(xian)(xian)圈使(shi)其像磁(ci)(ci)(ci)(ci)鐵(tie)(tie)一樣(yang)(yang)具有(you)(you)磁(ci)(ci)(ci)(ci)性(xing)的(de)(de)(de)裝置叫做電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)，通(tong)常(chang)制(zhi)成條形或(huo)(huo)(huo)蹄形。鐵(tie)(tie)心要用(yong)容易磁(ci)(ci)(ci)(ci)化，又容易消(xiao)失(shi)磁(ci)(ci)(ci)(ci)性(xing)的(de)(de)(de)軟鐵(tie)(tie)或(huo)(huo)(huo)硅(gui)鋼(gang)來制(zhi)做。這(zhe)樣(yang)(yang)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)在通(tong)電(dian)(dian)(dian)(dian)(dian)時(shi)有(you)(you)磁(ci)(ci)(ci)(ci)性(xing)，斷(duan)電(dian)(dian)(dian)(dian)(dian)后就隨(sui)之消(xiao)失(shi)。 電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有(you)(you)許(xu)多優點：電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)磁(ci)(ci)(ci)(ci)性(xing)的(de)(de)(de)有(you)(you)無，可以用(yong)通(tong)、斷(duan)電(dian)(dian)(dian)(dian)(dian)流控制(zhi)。磁(ci)(ci)(ci)(ci)性(xing)的(de)(de)(de)大小可以用(yong)電(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)強弱或(huo)(huo)(huo)線(xian)(xian)圈的(de)(de)(de)匝數來控制(zhi)。

電磁鐵的主要特點

1、采(cai)用(yong)全密封結構(gou)，防潮性能(neng)好。

2、經(jing)計(ji)算機優化設(she)計(ji)，結(jie)構合理、自重輕、吸力大(da)、能耗低。

3、勵磁線圈(quan)經特別工藝處理，提高了線圈(quan)的電器和機械性能，絕緣(yuan)資料(liao)熱等級到達(da)C級，運用壽命(ming)長。

4、普通(tong)型電磁(ci)鐵的額定通(tong)電持續率(lv)由曩昔的50%提高到60%，提高了電磁(ci)鐵的運用(yong)功(gong)率(lv)。

5、超(chao)高溫(wen)型電磁鐵采用獨特(te)隔熱方(fang)式，其間被吸(xi)物(wu)溫(wen)度有曩昔(xi)的(de)600℃提高700℃，擴大了電磁鐵的(de)適用范圍(wei)。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)能變(bian)換為機械(xie)能以(yi)實(shi)現(xian)吸(xi)合作功的(de)一(yi)種電(dian)(dian)(dian)器(qi)。通(tong)常由軟磁(ci)(ci)(ci)(ci)材(cai)料制成的(de)鐵(tie)(tie)(tie)心(xin)(xin)、銜鐵(tie)(tie)(tie)和勵磁(ci)(ci)(ci)(ci)繞組組成。當勵磁(ci)(ci)(ci)(ci)繞組通(tong)電(dian)(dian)(dian)時，繞組周圍(wei)產生磁(ci)(ci)(ci)(ci)場，鐵(tie)(tie)(tie)心(xin)(xin)磁(ci)(ci)(ci)(ci)化，并(bing)產生電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力吸(xi)引(yin)銜鐵(tie)(tie)(tie)，使之運動(dong)作功。電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)主要(yao)用(yong)(yong)(yong)于(yu)操動(dong)、牽引(yin)機械(xie)裝置，以(yi)達(da)到預期(qi)的(de)目的(de)。工業上常用(yong)(yong)(yong)的(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)有制動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、牽引(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、起重電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)和閥用(yong)(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。此外，屬于(yu)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)類的(de)還(huan)有用(yong)(yong)(yong)以(yi)傳遞或隔斷(duan)兩(liang)軸(zhou)間的(de)機械(xie)聯系的(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)聯軸(zhou)器(qi);用(yong)(yong)(yong)在機床工作臺(tai)上以(yi)吸(xi)牢磁(ci)(ci)(ci)(ci)性材(cai)料工件的(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)盤;供高(gao)能物理(li)、核聚(ju)變(bian)研究、磁(ci)(ci)(ci)(ci)流體(ti)發(fa)電(dian)(dian)(dian)和高(gao)速懸(xuan)浮(fu)列車等(deng)方面使用(yong)(yong)(yong)的(de)、能產生高(gao)達(da)數(shu)十特（斯拉）的(de)磁(ci)(ci)(ci)(ci)通(tong)密度而幾乎不(bu)消耗繞組功率的(de)超導電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。

起重電磁鐵

用(yong)來(lai)吊運和(he)裝(zhuang)卸鐵(tie)(tie)磁(ci)(ci)(ci)性(xing)物體(ti)的(de)電磁(ci)(ci)(ci)鐵(tie)(tie)。工(gong)業上(shang)常(chang)用(yong)以(yi)吊運或裝(zhuang)卸鐵(tie)(tie)礦石(shi)、鐵(tie)(tie)砂、廢(fei)鋼(gang)鐵(tie)(tie)、鋼(gang)錠、鋼(gang)軌以(yi)及各(ge)種鋼(gang)材(cai)和(he)鋼(gang)質(zhi)工(gong)件(jian)。起重電磁(ci)(ci)(ci)鐵(tie)(tie)通常(chang)做成圓盤形或矩形，并(bing)帶有內(nei)磁(ci)(ci)(ci)極(ji)和(he)外磁(ci)(ci)(ci)極(ji)。當勵磁(ci)(ci)(ci)繞組通電后，內(nei)外磁(ci)(ci)(ci)極(ji)均被磁(ci)(ci)(ci)化，吸引(yin)鋼(gang)質(zhi)材(cai)料或工(gong)件(jian)（相當于一(yi)般電磁(ci)(ci)(ci)鐵(tie)(tie)中的(de)銜鐵(tie)(tie)），形成一(yi)個閉合的(de)磁(ci)(ci)(ci)路。為保護勵磁(ci)(ci)(ci)繞組，使之(zhi)不因磁(ci)(ci)(ci)極(ji)與(yu)被吸引(yin)物體(ti)間的(de)機械撞擊所損傷(shang)，起重電磁(ci)(ci)(ci)鐵(tie)(tie)通常(chang)采用(yong)甲殼式結構，并(bing)且采用(yong)直流勵磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)和推(tui)斥(chi)機(ji)械(xie)(xie)裝(zhuang)(zhuang)(zhuang)置(zhi)用(yong)的(de)一種電磁(ci)鐵(tie)(tie)。主要用(yong)于各種自動(dong)設備中，以實現遠距離控制。為了能夠在(zai)(zai)長行(xing)程(cheng)下獲(huo)得較(jiao)大的(de)電磁(ci)吸(xi)(xi)力(li)，牽(qian)引(yin)電磁(ci)鐵(tie)(tie)一般采用(yong)吸(xi)(xi)引(yin)特(te)性比較(jiao)平坦的(de)甲(jia)殼(ke)式(shi)結構。其內部裝(zhuang)(zhuang)(zhuang)有鐵(tie)(tie)心(xin)、銜鐵(tie)(tie)和勵磁(ci)線圈(quan)。使用(yong)時，將(jiang)鐵(tie)(tie)心(xin)固(gu)定在(zai)(zai)機(ji)械(xie)(xie)裝(zhuang)(zhuang)(zhuang)置(zhi)的(de)靜止部件上，銜鐵(tie)(tie)則連接(jie)在(zai)(zai)牽(qian)引(yin)桿上。當勵磁(ci)繞組通電后，鐵(tie)(tie)心(xin)被磁(ci)化(hua)，產生電磁(ci)吸(xi)(xi)力(li)吸(xi)(xi)引(yin)銜鐵(tie)(tie)，后者則通過牽(qian)引(yin)桿來(lai)操縱所控制的(de)機(ji)械(xie)(xie)裝(zhuang)(zhuang)(zhuang)置(zhi)的(de)機(ji)構。為了適應不同控制對象的(de)需要，牽(qian)引(yin)電磁(ci)鐵(tie)(tie)有拉(la)動(dong)式(shi)和推(tui)動(dong)式(shi)兩(liang)種，但都不具備復位裝(zhuang)(zhuang)(zhuang)置(zhi)。牽(qian)引(yin)電磁(ci)鐵(tie)(tie)的(de)主要技術指(zhi)標(biao)為一定行(xing)程(cheng)下的(de)電磁(ci)吸(xi)(xi)力(li)、操作頻率和壽命。

制動電磁鐵

作(zuo)機械制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)用(yong)(yong)的(de)(de)(de)(de)(de)一種電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)。主要用(yong)(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)力驅(qu)動(dong)(dong)(dong)裝(zhuang)置和(he)起重運輸(shu)設備中，并(bing)(bing)與制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)配(pei)合使(shi)(shi)用(yong)(yong)，使(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機準確停(ting)車(che)和(he)懸(xuan)吊(diao)著的(de)(de)(de)(de)(de)重物(wu)不(bu)致墜(zhui)落。制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)按銜鐵(tie)行(xing)(xing)(xing)(xing)程分(fen)為長(chang)行(xing)(xing)(xing)(xing)程和(he)短行(xing)(xing)(xing)(xing)程兩類(lei)(lei);按勵(li)磁(ci)(ci)方式分(fen)為直流和(he)交(jiao)流、并(bing)(bing)勵(li)和(he)串勵(li)以(yi)及單相和(he)三相等種類(lei)(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的(de)(de)(de)(de)(de)工作(zuo)原理(li)是：當電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的(de)(de)(de)(de)(de)繞組通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)后(hou)，銜鐵(tie)被吸向(xiang)鐵(tie)心(xin)，并(bing)(bing)通(tong)(tong)過(guo)制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)中的(de)(de)(de)(de)(de)停(ting)檔壓迫制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿，使(shi)(shi)之移動(dong)(dong)(dong)，從而(er)迫使(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)松(song)閘。切斷線圈電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)后(hou)，制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿在(zai)彈簧(huang)作(zuo)用(yong)(yong)下使(shi)(shi)銜鐵(tie)脫離磁(ci)(ci)軛(e)，而(er)制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)則將機構剎(cha)住。制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的(de)(de)(de)(de)(de)主要技術參(can)數是行(xing)(xing)(xing)(xing)程、一定行(xing)(xing)(xing)(xing)程下的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)吸力、操作(zuo)頻率和(he)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持續率。操作(zuo)頻率是指(zhi)每(mei)小時(shi)操作(zuo)的(de)(de)(de)(de)(de)次數;通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持續率是指(zhi)每(mei)次通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間與每(mei)次通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)及不(bu)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間之和(he)的(de)(de)(de)(de)(de)百分(fen)比。使(shi)(shi)用(yong)(yong)中，制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)與瓦式制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)相配(pei)合時(shi)用(yong)(yong)短行(xing)(xing)(xing)(xing)程類(lei)(lei);與皮帶制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)相配(pei)合時(shi)用(yong)(yong)長(chang)行(xing)(xing)(xing)(xing)程類(lei)(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)通(tong)(tong)過(guo)液(ye)壓方式將電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)力傳遞(di)給制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)機構的(de)(de)(de)(de)(de)稱液(ye)壓制(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)。

閥用電磁鐵

供(gong)遠距離(li)操(cao)作(zuo)各種液壓(ya)、氣(qi)動(dong)系統閥(fa)(fa)門(men)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用(yong)(yong)于各種金屬切削機(ji)床中。閥(fa)(fa)用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設復(fu)位(wei)(wei)裝置，而(er)由閥(fa)(fa)體中的(de)(de)(de)彈簧使(shi)之復(fu)位(wei)(wei)。當電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)勵磁(ci)(ci)(ci)繞組(zu)通過電(dian)(dian)(dian)流時，電(dian)(dian)(dian)磁(ci)(ci)(ci)吸力(li)即克服彈簧阻(zu)力(li)，使(shi)閥(fa)(fa)體的(de)(de)(de)推(tui)桿移動(dong)，將閥(fa)(fa)門(men)開啟;當勵磁(ci)(ci)(ci)繞組(zu)斷電(dian)(dian)(dian)后，在復(fu)位(wei)(wei)彈簧作(zuo)用(yong)(yong)下，閥(fa)(fa)體推(tui)桿便推(tui)動(dong)銜(xian)(xian)鐵(tie)(tie)，使(shi)其移動(dong)額定行(xing)程處，閥(fa)(fa)門(men)關閉。閥(fa)(fa)用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分為濕(shi)式和干式兩(liang)種。濕(shi)式閥(fa)(fa)用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)銜(xian)(xian)鐵(tie)(tie)在液壓(ya)油(you)中工作(zuo)，由于油(you)的(de)(de)(de)冷卻作(zuo)用(yong)(yong)，使(shi)其與具(ju)有相同吸力(li)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相比(bi)，有較小的(de)(de)(de)尺寸。

電磁鐵的應用

門(men)(men)禁：為什么門(men)(men)禁可(ke)以(yi)在(zai)沒刷卡時(shi)把(ba)門(men)(men)牢牢的(de)“抓住”？原來(lai)單元(yuan)門(men)(men)是由鋼材料做成的(de)，那個金(jin)(jin)屬體(ti)在(zai)通(tong)電時(shi)可(ke)以(yi)產(chan)生強大(da)的(de)磁場，產(chan)生的(de)磁力(li)能(neng)把(ba)門(men)(men)牢牢的(de)吸(xi)住，而刷卡的(de)瞬間，切(qie)斷電流，金(jin)(jin)屬體(ti)失去磁性，我們就(jiu)可(ke)以(yi)打開門(men)(men)了。那個金(jin)(jin)屬體(ti)其實是一塊電磁鐵。

電(dian)(dian)磁(ci)起(qi)重機：最(zui)直接的應用之一(yi)是電(dian)(dian)磁(ci)起(qi)重機。電(dian)(dian)磁(ci)鐵(tie)安裝在吊車上，通電(dian)(dian)后(hou)吸(xi)起(qi)大量鋼鐵(tie)，移動到另一(yi)個位置后(hou)切斷電(dian)(dian)流，鋼鐵(tie)被放(fang)下，免去了(le)打捆的麻煩(fan)。大型電(dian)(dian)磁(ci)起(qi)重機一(yi)次可以吊起(qi)幾噸鋼材。

在電動機(ji)、發(fa)電機(ji)、電鈴和電磁繼電器里(li)也(ye)(ye)用到電磁鐵。全自動洗(xi)衣機(ji)的進水(shui)、排水(shui)閥(fa)門(men)，衛生間里(li)感應(ying)式沖水(shui)器的閥(fa)門(men)，也(ye)(ye)都是由電磁鐵控制的。

電(dian)(dian)磁鐵(tie)(tie)的另一(yi)個應用是產生強磁場(chang)。現代技術(shu)中很(hen)多地方需要的強磁場(chang)都由電(dian)(dian)磁鐵(tie)(tie)提供，如大型(xing)電(dian)(dian)動機(ji)、發電(dian)(dian)機(ji)、磁療(liao)設備等。