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。這實際上是電磁鐵原理(li)的(de)(de)最初發現。1823年(nian)，斯特金也(ye)做了(le)一次類似的(de)(de)實驗：他在(zai)一根并非是磁(ci)鐵(tie)(tie)棒(bang)的(de)(de)U型(xing)鐵(tie)(tie)棒(bang)上(shang)繞了(le)18圈銅(tong)(tong)裸線(xian)，當銅(tong)(tong)線(xian)與伏打電(dian)池接(jie)通時(shi)，繞在(zai)U型(xing)鐵(tie)(tie)棒(bang)上(shang)的(de)(de)銅(tong)(tong)線(xian)圈即產生了(le)密集的(de)(de)磁(ci)場(chang)，這樣就使U型(xing)鐵(tie)(tie)棒(bang)變成(cheng)了(le)一塊“電(dian)磁(ci)鐵(tie)(tie)”。這種電(dian)磁(ci)鐵(tie)(tie)上(shang)的(de)(de)磁(ci)能(neng)要比永磁(ci)能(neng)大放多倍，它能(neng)吸起比它重20倍的(de)(de)鐵(tie)(tie)塊，而(er)當電(dian)源切斷(duan)后，U型(xing)鐵(tie)(tie)棒(bang)就什么鐵(tie)(tie)塊也(ye)吸不住(zhu)，重新成(cheng)為一根普通的(de)(de)鐵(tie)(tie)棒(bang)。

斯特金的(de)電磁鐵發明，使人們看到了把(ba)電能轉化為磁能的(de)光(guang)明前景，這一發明很(hen)快在英(ying)國、美國以(yi)及西歐一些(xie)沿海國家傳播(bo)開來。

1829年，美國電(dian)(dian)學家亨利對斯(si)特金電(dian)(dian)磁(ci)鐵(tie)(tie)裝置(zhi)進行了一(yi)些(xie)革新(xin)，絕緣導(dao)(dao)線(xian)代替(ti)裸銅導(dao)(dao)線(xian)，因此不(bu)必擔心被銅導(dao)(dao)線(xian)過分靠近而短路。由于(yu)導(dao)(dao)線(xian)有了絕緣層，就(jiu)(jiu)可以將它們一(yi)圈圈地(di)緊(jin)緊(jin)地(di)繞在一(yi)起，由于(yu)線(xian)圈越(yue)密集，產生的(de)磁(ci)場就(jiu)(jiu)越(yue)強，這樣就(jiu)(jiu)大大提(ti)高了把電(dian)(dian)能(neng)轉化為磁(ci)能(neng)的(de)能(neng)力(li)。到了1831年，亨利試制出(chu)了一(yi)塊更新(xin)的(de)電(dian)(dian)磁(ci)鐵(tie)(tie)，雖(sui)然它的(de)體積并不(bu)大，但它能(neng)吸起1噸重的(de)鐵(tie)(tie)塊。

電磁(ci)(ci)(ci)鐵(tie)內部帶有鐵(tie)心的(de)、利用(yong)通(tong)有電流的(de)線(xian)圈(quan)使(shi)其像磁(ci)(ci)(ci)鐵(tie)一(yi)樣具有磁(ci)(ci)(ci)性(xing)的(de)裝(zhuang)置叫做電磁(ci)(ci)(ci)鐵(tie)，通(tong)常制成條形(xing)(xing)或蹄形(xing)(xing)。鐵(tie)心要用(yong)容易磁(ci)(ci)(ci)化，又容易消失(shi)磁(ci)(ci)(ci)性(xing)的(de)軟鐵(tie)或硅鋼來(lai)制做。這樣的(de)電磁(ci)(ci)(ci)鐵(tie)在通(tong)電時有磁(ci)(ci)(ci)性(xing)，斷電后就隨(sui)之消失(shi)。 電磁(ci)(ci)(ci)鐵(tie)有許多優點：電磁(ci)(ci)(ci)鐵(tie)磁(ci)(ci)(ci)性(xing)的(de)有無，可以(yi)用(yong)通(tong)、斷電流控制。磁(ci)(ci)(ci)性(xing)的(de)大小可以(yi)用(yong)電流的(de)強(qiang)弱或線(xian)圈(quan)的(de)匝數來(lai)控制。

電磁鐵的主要特點

1、采用全密封結(jie)構，防(fang)潮性(xing)能好。

2、經計算(suan)機優化(hua)設計，結構(gou)合理、自重輕、吸力大、能耗低(di)。

3、勵磁線圈經(jing)特別工藝處理，提高(gao)了線圈的(de)電器和機械性能，絕(jue)緣資料熱等級(ji)到達C級(ji)，運用壽命長(chang)。

4、普通型電磁鐵的額(e)定通電持續率(lv)由(you)曩昔(xi)的50%提高(gao)到60%，提高(gao)了電磁鐵的運用功率(lv)。

5、超高溫型電磁(ci)鐵采(cai)用(yong)(yong)獨特(te)隔熱方(fang)式，其(qi)間被(bei)吸物溫度有曩昔的600℃提高700℃，擴大了電磁(ci)鐵的適(shi)用(yong)(yong)范圍。

6、裝置、運轉、保護簡(jian)潔。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)能變(bian)換為機械(xie)能以實現吸(xi)(xi)合(he)作功(gong)(gong)的(de)一(yi)種電(dian)(dian)(dian)(dian)(dian)(dian)器。通(tong)常由軟磁(ci)(ci)(ci)(ci)(ci)(ci)材料(liao)(liao)制成的(de)鐵(tie)(tie)心(xin)、銜鐵(tie)(tie)和(he)勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組(zu)組(zu)成。當勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組(zu)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，繞組(zu)周圍產(chan)生磁(ci)(ci)(ci)(ci)(ci)(ci)場，鐵(tie)(tie)心(xin)磁(ci)(ci)(ci)(ci)(ci)(ci)化，并(bing)產(chan)生電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)吸(xi)(xi)引銜鐵(tie)(tie)，使之(zhi)運動作功(gong)(gong)。電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)主(zhu)要用(yong)于操動、牽引機械(xie)裝置，以達到預期的(de)目的(de)。工(gong)(gong)業上(shang)常用(yong)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)有(you)制動電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)、牽引電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)、起重電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)和(he)閥用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)等(deng)。此外，屬(shu)于電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)類的(de)還有(you)用(yong)以傳(chuan)遞或隔斷(duan)兩軸間(jian)的(de)機械(xie)聯(lian)系的(de)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)聯(lian)軸器;用(yong)在機床工(gong)(gong)作臺上(shang)以吸(xi)(xi)牢(lao)磁(ci)(ci)(ci)(ci)(ci)(ci)性(xing)材料(liao)(liao)工(gong)(gong)件(jian)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)(xi)盤;供(gong)高(gao)能物理(li)、核(he)聚變(bian)研究、磁(ci)(ci)(ci)(ci)(ci)(ci)流體發電(dian)(dian)(dian)(dian)(dian)(dian)和(he)高(gao)速(su)懸(xuan)浮列車等(deng)方面使用(yong)的(de)、能產(chan)生高(gao)達數十特（斯拉(la)）的(de)磁(ci)(ci)(ci)(ci)(ci)(ci)通(tong)密度而(er)幾乎不消耗繞組(zu)功(gong)(gong)率(lv)的(de)超導(dao)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)等(deng)。

起重電磁鐵

用(yong)來吊運和裝(zhuang)卸鐵(tie)(tie)(tie)磁(ci)(ci)(ci)性物體(ti)的(de)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。工業上常(chang)用(yong)以(yi)(yi)吊運或裝(zhuang)卸鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂、廢鋼鐵(tie)(tie)(tie)、鋼錠、鋼軌以(yi)(yi)及(ji)各種鋼材和鋼質(zhi)工件。起重(zhong)(zhong)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常(chang)做成(cheng)圓盤形(xing)(xing)(xing)或矩形(xing)(xing)(xing)，并帶有內磁(ci)(ci)(ci)極(ji)(ji)和外磁(ci)(ci)(ci)極(ji)(ji)。當(dang)勵磁(ci)(ci)(ci)繞組通電(dian)后，內外磁(ci)(ci)(ci)極(ji)(ji)均被(bei)磁(ci)(ci)(ci)化，吸引鋼質(zhi)材料或工件（相當(dang)于一(yi)(yi)般(ban)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)中的(de)銜鐵(tie)(tie)(tie)），形(xing)(xing)(xing)成(cheng)一(yi)(yi)個閉(bi)合的(de)磁(ci)(ci)(ci)路。為保(bao)護(hu)勵磁(ci)(ci)(ci)繞組，使之不因磁(ci)(ci)(ci)極(ji)(ji)與被(bei)吸引物體(ti)間(jian)的(de)機械撞擊所損傷，起重(zhong)(zhong)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常(chang)采(cai)用(yong)甲殼式結構(gou)，并且采(cai)用(yong)直流勵磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)(qian)引(yin)(yin)和推斥(chi)機械裝(zhuang)置用的(de)(de)一種(zhong)電(dian)(dian)(dian)(dian)磁鐵(tie)。主要(yao)用于各(ge)種(zhong)自動設備(bei)中，以實現(xian)遠(yuan)距離控(kong)制(zhi)。為(wei)(wei)了能(neng)夠(gou)在長行(xing)程下獲(huo)得較(jiao)大的(de)(de)電(dian)(dian)(dian)(dian)磁吸力，牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)(dian)磁鐵(tie)一般采用吸引(yin)(yin)特(te)性(xing)比較(jiao)平(ping)坦的(de)(de)甲殼(ke)式(shi)結構(gou)。其內部裝(zhuang)有(you)鐵(tie)心(xin)、銜(xian)鐵(tie)和勵磁線圈。使(shi)用時，將鐵(tie)心(xin)固定(ding)在機械裝(zhuang)置的(de)(de)靜止部件上(shang)，銜(xian)鐵(tie)則(ze)連接(jie)在牽(qian)(qian)引(yin)(yin)桿上(shang)。當勵磁繞組通電(dian)(dian)(dian)(dian)后(hou)，鐵(tie)心(xin)被磁化，產生電(dian)(dian)(dian)(dian)磁吸力吸引(yin)(yin)銜(xian)鐵(tie)，后(hou)者則(ze)通過牽(qian)(qian)引(yin)(yin)桿來(lai)操(cao)縱所(suo)控(kong)制(zhi)的(de)(de)機械裝(zhuang)置的(de)(de)機構(gou)。為(wei)(wei)了適應(ying)不同(tong)控(kong)制(zhi)對象的(de)(de)需(xu)要(yao)，牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)(dian)磁鐵(tie)有(you)拉動式(shi)和推動式(shi)兩種(zhong)，但都不具備(bei)復位裝(zhuang)置。牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)(dian)磁鐵(tie)的(de)(de)主要(yao)技術指標為(wei)(wei)一定(ding)行(xing)程下的(de)(de)電(dian)(dian)(dian)(dian)磁吸力、操(cao)作頻率和壽命。

制動電磁鐵

作(zuo)(zuo)(zuo)機械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)用的(de)(de)一種電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)。主(zhu)要用于(yu)電(dian)(dian)(dian)力(li)驅(qu)動(dong)(dong)(dong)裝置和(he)(he)(he)(he)起重運輸(shu)設備中，并(bing)與(yu)(yu)(yu)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)配合使(shi)用，使(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機準確停車和(he)(he)(he)(he)懸(xuan)吊著的(de)(de)重物不致墜落。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)按銜(xian)(xian)鐵(tie)(tie)(tie)行(xing)(xing)程(cheng)(cheng)分(fen)為長行(xing)(xing)程(cheng)(cheng)和(he)(he)(he)(he)短(duan)行(xing)(xing)程(cheng)(cheng)兩類(lei)(lei)(lei);按勵(li)磁方式分(fen)為直流和(he)(he)(he)(he)交流、并(bing)勵(li)和(he)(he)(he)(he)串勵(li)以及(ji)單(dan)相(xiang)和(he)(he)(he)(he)三相(xiang)等種類(lei)(lei)(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)的(de)(de)工作(zuo)(zuo)(zuo)原理是：當電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)的(de)(de)繞組通(tong)(tong)電(dian)(dian)(dian)后，銜(xian)(xian)鐵(tie)(tie)(tie)被吸(xi)向(xiang)鐵(tie)(tie)(tie)心，并(bing)通(tong)(tong)過制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)中的(de)(de)停檔壓(ya)迫制(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿，使(shi)之移動(dong)(dong)(dong)，從(cong)而迫使(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)松閘(zha)。切斷(duan)線圈(quan)電(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿在彈簧作(zuo)(zuo)(zuo)用下使(shi)銜(xian)(xian)鐵(tie)(tie)(tie)脫離磁軛(e)，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)則將機構剎(cha)住。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)的(de)(de)主(zhu)要技術參數(shu)(shu)是行(xing)(xing)程(cheng)(cheng)、一定行(xing)(xing)程(cheng)(cheng)下的(de)(de)電(dian)(dian)(dian)磁吸(xi)力(li)、操(cao)作(zuo)(zuo)(zuo)頻(pin)率(lv)和(he)(he)(he)(he)通(tong)(tong)電(dian)(dian)(dian)持(chi)續率(lv)。操(cao)作(zuo)(zuo)(zuo)頻(pin)率(lv)是指每(mei)小時操(cao)作(zuo)(zuo)(zuo)的(de)(de)次數(shu)(shu);通(tong)(tong)電(dian)(dian)(dian)持(chi)續率(lv)是指每(mei)次通(tong)(tong)電(dian)(dian)(dian)時間與(yu)(yu)(yu)每(mei)次通(tong)(tong)電(dian)(dian)(dian)及(ji)不通(tong)(tong)電(dian)(dian)(dian)時間之和(he)(he)(he)(he)的(de)(de)百分(fen)比。使(shi)用中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)與(yu)(yu)(yu)瓦式制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)相(xiang)配合時用短(duan)行(xing)(xing)程(cheng)(cheng)類(lei)(lei)(lei);與(yu)(yu)(yu)皮帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)相(xiang)配合時用長行(xing)(xing)程(cheng)(cheng)類(lei)(lei)(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)通(tong)(tong)過液(ye)壓(ya)方式將電(dian)(dian)(dian)磁力(li)傳(chuan)遞(di)給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)機構的(de)(de)稱液(ye)壓(ya)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁鐵(tie)(tie)(tie)。

閥用電磁鐵

供遠距離(li)操(cao)作各種液壓、氣(qi)動系統閥(fa)門(men)的(de)(de)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。常(chang)用(yong)于各種金屬切削機床中。閥(fa)用(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)不設復(fu)位裝置(zhi)，而由(you)閥(fa)體(ti)(ti)中的(de)(de)彈簧使(shi)之復(fu)位。當(dang)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)勵(li)磁(ci)(ci)繞組通過電(dian)流(liu)時，電(dian)磁(ci)(ci)吸力即(ji)克服彈簧阻力，使(shi)閥(fa)體(ti)(ti)的(de)(de)推(tui)桿移動，將閥(fa)門(men)開啟(qi);當(dang)勵(li)磁(ci)(ci)繞組斷電(dian)后，在(zai)復(fu)位彈簧作用(yong)下，閥(fa)體(ti)(ti)推(tui)桿便推(tui)動銜(xian)鐵(tie)(tie)(tie)，使(shi)其移動額(e)定行程處，閥(fa)門(men)關閉(bi)。閥(fa)用(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)分(fen)為濕式和干式兩種。濕式閥(fa)用(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)銜(xian)鐵(tie)(tie)(tie)在(zai)液壓油中工作，由(you)于油的(de)(de)冷(leng)卻作用(yong)，使(shi)其與具有(you)相(xiang)(xiang)同吸力的(de)(de)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)相(xiang)(xiang)比，有(you)較小的(de)(de)尺寸。

電磁鐵的應用

門禁：為什么門禁可(ke)以(yi)在沒刷卡時把門牢(lao)牢(lao)的(de)(de)“抓(zhua)住(zhu)”？原來單元門是由鋼材(cai)料做成(cheng)的(de)(de)，那(nei)個金屬(shu)體在通(tong)電(dian)時可(ke)以(yi)產(chan)生強大的(de)(de)磁(ci)(ci)場，產(chan)生的(de)(de)磁(ci)(ci)力能(neng)把門牢(lao)牢(lao)的(de)(de)吸住(zhu)，而(er)刷卡的(de)(de)瞬間，切斷電(dian)流，金屬(shu)體失去磁(ci)(ci)性(xing)，我們就可(ke)以(yi)打開門了(le)。那(nei)個金屬(shu)體其實是一塊電(dian)磁(ci)(ci)鐵。

電(dian)(dian)(dian)磁(ci)(ci)起(qi)(qi)重機：最(zui)直(zhi)接的應用之一(yi)是(shi)電(dian)(dian)(dian)磁(ci)(ci)起(qi)(qi)重機。電(dian)(dian)(dian)磁(ci)(ci)鐵安裝在(zai)吊車上，通電(dian)(dian)(dian)后吸起(qi)(qi)大量(liang)鋼鐵，移動到另(ling)一(yi)個位置后切(qie)斷電(dian)(dian)(dian)流，鋼鐵被放下，免(mian)去了打捆的麻(ma)煩。大型電(dian)(dian)(dian)磁(ci)(ci)起(qi)(qi)重機一(yi)次可以吊起(qi)(qi)幾噸鋼材。

在電(dian)(dian)(dian)動(dong)機、發電(dian)(dian)(dian)機、電(dian)(dian)(dian)鈴和電(dian)(dian)(dian)磁(ci)繼(ji)電(dian)(dian)(dian)器里也用到電(dian)(dian)(dian)磁(ci)鐵。全自動(dong)洗衣機的進水(shui)、排(pai)水(shui)閥門，衛生(sheng)間里感應式沖水(shui)器的閥門，也都是(shi)由電(dian)(dian)(dian)磁(ci)鐵控制的。

電(dian)磁(ci)鐵(tie)的(de)另一個應用是產生強磁(ci)場。現代(dai)技(ji)術中很多地方需(xu)要的(de)強磁(ci)場都由電(dian)磁(ci)鐵(tie)提供，如大型電(dian)動機、發電(dian)機、磁(ci)療(liao)設(she)備等。