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。這實際上是呼和浩特電磁鐵原理的(de)(de)(de)最(zui)初發現。1823年，斯特金也(ye)做了(le)一(yi)次(ci)類似(si)的(de)(de)(de)實驗：他在一(yi)根并非(fei)是磁(ci)(ci)鐵棒(bang)(bang)的(de)(de)(de)U型鐵棒(bang)(bang)上(shang)繞了(le)18圈銅裸線(xian)，當銅線(xian)與伏(fu)打電池接通(tong)(tong)時，繞在U型鐵棒(bang)(bang)上(shang)的(de)(de)(de)銅線(xian)圈即(ji)產生了(le)密集的(de)(de)(de)磁(ci)(ci)場，這樣就(jiu)使U型鐵棒(bang)(bang)變(bian)成了(le)一(yi)塊“電磁(ci)(ci)鐵”。這種電磁(ci)(ci)鐵上(shang)的(de)(de)(de)磁(ci)(ci)能要比(bi)永磁(ci)(ci)能大(da)放多倍，它(ta)能吸起比(bi)它(ta)重(zhong)20倍的(de)(de)(de)鐵塊，而當電源(yuan)切(qie)斷后，U型鐵棒(bang)(bang)就(jiu)什么(me)鐵塊也(ye)吸不住(zhu)，重(zhong)新成為一(yi)根普通(tong)(tong)的(de)(de)(de)鐵棒(bang)(bang)。

斯特金的電(dian)磁鐵發明，使人們(men)看(kan)到了把電(dian)能(neng)轉化為磁能(neng)的光(guang)明前景(jing)，這(zhe)一發明很快(kuai)在英(ying)國(guo)、美國(guo)以及西歐(ou)一些(xie)沿海(hai)國(guo)家傳(chuan)播開來。

1829年，美(mei)國電(dian)學家亨(heng)利對斯(si)特(te)金電(dian)磁(ci)(ci)(ci)鐵裝置進行(xing)了(le)(le)一(yi)些(xie)革新，絕緣(yuan)導(dao)線代替(ti)裸(luo)銅導(dao)線，因此(ci)不必擔心被(bei)銅導(dao)線過分(fen)靠(kao)近而短(duan)路。由于導(dao)線有了(le)(le)絕緣(yuan)層，就可以將(jiang)它(ta)們一(yi)圈圈地緊緊地繞在一(yi)起(qi)，由于線圈越(yue)密集，產生的(de)(de)磁(ci)(ci)(ci)場就越(yue)強，這樣(yang)就大大提高了(le)(le)把電(dian)能轉化為磁(ci)(ci)(ci)能的(de)(de)能力。到了(le)(le)1831年，亨(heng)利試制出(chu)了(le)(le)一(yi)塊(kuai)更新的(de)(de)電(dian)磁(ci)(ci)(ci)鐵，雖(sui)然它(ta)的(de)(de)體積并不大，但它(ta)能吸(xi)起(qi)1噸重的(de)(de)鐵塊(kuai)。

電磁(ci)(ci)(ci)鐵內部帶(dai)有(you)鐵心的(de)(de)、利用(yong)通有(you)電流的(de)(de)線(xian)圈使(shi)其像磁(ci)(ci)(ci)鐵一(yi)樣具有(you)磁(ci)(ci)(ci)性(xing)的(de)(de)裝(zhuang)置(zhi)叫做電磁(ci)(ci)(ci)鐵，通常制成(cheng)條形(xing)或蹄(ti)形(xing)。鐵心要用(yong)容(rong)易磁(ci)(ci)(ci)化，又容(rong)易消失磁(ci)(ci)(ci)性(xing)的(de)(de)軟(ruan)鐵或硅鋼(gang)來(lai)制做。這樣的(de)(de)電磁(ci)(ci)(ci)鐵在通電時有(you)磁(ci)(ci)(ci)性(xing)，斷(duan)電后(hou)就(jiu)隨之消失。 電磁(ci)(ci)(ci)鐵有(you)許多優點：電磁(ci)(ci)(ci)鐵磁(ci)(ci)(ci)性(xing)的(de)(de)有(you)無，可(ke)以(yi)用(yong)通、斷(duan)電流控制。磁(ci)(ci)(ci)性(xing)的(de)(de)大小可(ke)以(yi)用(yong)電流的(de)(de)強弱或線(xian)圈的(de)(de)匝數(shu)來(lai)控制。

電磁鐵的主要特點

1、采用(yong)全(quan)密封結構，防潮(chao)性(xing)能好。

2、經(jing)計算機優化設計，結構合理、自重輕、吸力大、能耗(hao)低。

3、勵磁線(xian)(xian)圈(quan)經特別工(gong)藝處理，提(ti)高(gao)了線(xian)(xian)圈(quan)的(de)電(dian)器和(he)機械性能，絕(jue)緣資料熱等級(ji)(ji)到達C級(ji)(ji)，運用壽命(ming)長。

4、普通(tong)型電(dian)磁(ci)鐵的(de)額定通(tong)電(dian)持續(xu)率由(you)曩昔的(de)50%提高到60%，提高了電(dian)磁(ci)鐵的(de)運用(yong)功率。

5、超高(gao)溫(wen)型(xing)電磁鐵采用獨特隔熱(re)方式(shi)，其間被吸物溫(wen)度有曩昔的(de)600℃提高(gao)700℃，擴大(da)了(le)電磁鐵的(de)適(shi)用范圍。

6、裝(zhuang)置(zhi)、運轉、保護簡(jian)潔。

電磁鐵工作原理

將電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)能變換為機械能以(yi)實現吸(xi)(xi)合作功的一種電(dian)器(qi)。通(tong)常由軟(ruan)磁(ci)(ci)(ci)(ci)(ci)(ci)材料制成(cheng)的鐵(tie)(tie)(tie)(tie)(tie)心、銜鐵(tie)(tie)(tie)(tie)(tie)和(he)勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組組成(cheng)。當勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組通(tong)電(dian)時，繞組周圍產生(sheng)磁(ci)(ci)(ci)(ci)(ci)(ci)場，鐵(tie)(tie)(tie)(tie)(tie)心磁(ci)(ci)(ci)(ci)(ci)(ci)化，并產生(sheng)電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)(yin)(yin)銜鐵(tie)(tie)(tie)(tie)(tie)，使之運動(dong)作功。電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)主要用(yong)(yong)(yong)于操動(dong)、牽(qian)引(yin)(yin)(yin)機械裝置，以(yi)達到預期的目的。工業上常用(yong)(yong)(yong)的電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)有制動(dong)電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)、牽(qian)引(yin)(yin)(yin)電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)、起重電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)和(he)閥用(yong)(yong)(yong)電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)等。此外，屬于電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)類的還有用(yong)(yong)(yong)以(yi)傳遞或隔(ge)斷兩(liang)軸(zhou)(zhou)間的機械聯系的電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)聯軸(zhou)(zhou)器(qi);用(yong)(yong)(yong)在機床工作臺上以(yi)吸(xi)(xi)牢磁(ci)(ci)(ci)(ci)(ci)(ci)性材料工件的電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)(xi)盤;供高能物理、核聚變研究、磁(ci)(ci)(ci)(ci)(ci)(ci)流體發電(dian)和(he)高速懸浮列車等方面使用(yong)(yong)(yong)的、能產生(sheng)高達數十特（斯拉）的磁(ci)(ci)(ci)(ci)(ci)(ci)通(tong)密度而幾乎(hu)不消耗繞組功率的超導電(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)等。

起重電磁鐵

用(yong)來(lai)吊運(yun)和(he)裝卸鐵(tie)(tie)(tie)磁(ci)性物(wu)體的(de)(de)電磁(ci)鐵(tie)(tie)(tie)。工業(ye)上(shang)常用(yong)以吊運(yun)或裝卸鐵(tie)(tie)(tie)礦石(shi)、鐵(tie)(tie)(tie)砂、廢鋼(gang)鐵(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌以及各種(zhong)鋼(gang)材和(he)鋼(gang)質工件(jian)(jian)。起重(zhong)(zhong)電磁(ci)鐵(tie)(tie)(tie)通(tong)常做成(cheng)圓盤形或矩形，并帶有內磁(ci)極(ji)(ji)和(he)外磁(ci)極(ji)(ji)。當勵(li)磁(ci)繞(rao)組通(tong)電后，內外磁(ci)極(ji)(ji)均(jun)被磁(ci)化，吸引鋼(gang)質材料或工件(jian)(jian)（相當于一般電磁(ci)鐵(tie)(tie)(tie)中的(de)(de)銜(xian)鐵(tie)(tie)(tie)），形成(cheng)一個閉(bi)合的(de)(de)磁(ci)路。為保護勵(li)磁(ci)繞(rao)組，使之不(bu)因磁(ci)極(ji)(ji)與被吸引物(wu)體間的(de)(de)機械撞擊所損傷，起重(zhong)(zhong)電磁(ci)鐵(tie)(tie)(tie)通(tong)常采用(yong)甲殼式結(jie)構，并且采用(yong)直流勵(li)磁(ci)。

牽引電磁鐵

供牽(qian)(qian)引(yin)(yin)(yin)(yin)和(he)(he)推斥機(ji)(ji)械(xie)裝(zhuang)(zhuang)置用的(de)(de)(de)一(yi)種電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。主(zhu)要(yao)用于各種自動設備中，以實現遠距離(li)控制。為(wei)了(le)能夠在長(chang)行(xing)程下獲得較(jiao)大的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)吸力，牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)一(yi)般采用吸引(yin)(yin)(yin)(yin)特性比較(jiao)平坦的(de)(de)(de)甲殼式結構。其內(nei)部裝(zhuang)(zhuang)有(you)鐵(tie)(tie)心、銜鐵(tie)(tie)和(he)(he)勵磁(ci)(ci)(ci)線(xian)圈。使(shi)用時，將(jiang)鐵(tie)(tie)心固(gu)定在機(ji)(ji)械(xie)裝(zhuang)(zhuang)置的(de)(de)(de)靜(jing)止部件上，銜鐵(tie)(tie)則連接在牽(qian)(qian)引(yin)(yin)(yin)(yin)桿上。當勵磁(ci)(ci)(ci)繞組通(tong)(tong)電(dian)(dian)(dian)后(hou)，鐵(tie)(tie)心被磁(ci)(ci)(ci)化，產生電(dian)(dian)(dian)磁(ci)(ci)(ci)吸力吸引(yin)(yin)(yin)(yin)銜鐵(tie)(tie)，后(hou)者則通(tong)(tong)過牽(qian)(qian)引(yin)(yin)(yin)(yin)桿來(lai)操(cao)縱所控制的(de)(de)(de)機(ji)(ji)械(xie)裝(zhuang)(zhuang)置的(de)(de)(de)機(ji)(ji)構。為(wei)了(le)適應不同控制對象的(de)(de)(de)需要(yao)，牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)有(you)拉(la)動式和(he)(he)推動式兩種，但都不具備復位裝(zhuang)(zhuang)置。牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)主(zhu)要(yao)技術指(zhi)標為(wei)一(yi)定行(xing)程下的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)吸力、操(cao)作(zuo)頻率和(he)(he)壽命。

制動電磁鐵

作機(ji)械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)用(yong)(yong)(yong)的(de)(de)一種電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)。主(zhu)要(yao)用(yong)(yong)(yong)于電(dian)(dian)(dian)力(li)(li)驅動(dong)(dong)(dong)裝置(zhi)和(he)起重運輸設備中(zhong)，并與(yu)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)配(pei)合使(shi)(shi)用(yong)(yong)(yong)，使(shi)(shi)電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)準確停(ting)車和(he)懸吊著的(de)(de)重物不致墜落(luo)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)按銜(xian)鐵(tie)(tie)(tie)(tie)行(xing)程(cheng)(cheng)分(fen)為(wei)長行(xing)程(cheng)(cheng)和(he)短行(xing)程(cheng)(cheng)兩(liang)類(lei);按勵(li)磁(ci)方(fang)式(shi)分(fen)為(wei)直流和(he)交流、并勵(li)和(he)串勵(li)以(yi)及單相(xiang)(xiang)和(he)三相(xiang)(xiang)等(deng)種類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)的(de)(de)工(gong)作原(yuan)理是：當(dang)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)的(de)(de)繞組通(tong)(tong)電(dian)(dian)(dian)后，銜(xian)鐵(tie)(tie)(tie)(tie)被吸向鐵(tie)(tie)(tie)(tie)心，并通(tong)(tong)過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)中(zhong)的(de)(de)停(ting)檔壓迫制(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿，使(shi)(shi)之移動(dong)(dong)(dong)，從而迫使(shi)(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)松閘(zha)。切斷線圈電(dian)(dian)(dian)源(yuan)后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿在彈簧作用(yong)(yong)(yong)下使(shi)(shi)銜(xian)鐵(tie)(tie)(tie)(tie)脫(tuo)離磁(ci)軛(e)，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)則將機(ji)構剎住(zhu)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)的(de)(de)主(zhu)要(yao)技術參數(shu)是行(xing)程(cheng)(cheng)、一定行(xing)程(cheng)(cheng)下的(de)(de)電(dian)(dian)(dian)磁(ci)吸力(li)(li)、操(cao)作頻率和(he)通(tong)(tong)電(dian)(dian)(dian)持續率。操(cao)作頻率是指(zhi)每小時(shi)操(cao)作的(de)(de)次數(shu);通(tong)(tong)電(dian)(dian)(dian)持續率是指(zhi)每次通(tong)(tong)電(dian)(dian)(dian)時(shi)間與(yu)每次通(tong)(tong)電(dian)(dian)(dian)及不通(tong)(tong)電(dian)(dian)(dian)時(shi)間之和(he)的(de)(de)百分(fen)比。使(shi)(shi)用(yong)(yong)(yong)中(zhong)，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)與(yu)瓦(wa)式(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)相(xiang)(xiang)配(pei)合時(shi)用(yong)(yong)(yong)短行(xing)程(cheng)(cheng)類(lei);與(yu)皮(pi)帶(dai)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)相(xiang)(xiang)配(pei)合時(shi)用(yong)(yong)(yong)長行(xing)程(cheng)(cheng)類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)通(tong)(tong)過(guo)液壓方(fang)式(shi)將電(dian)(dian)(dian)磁(ci)力(li)(li)傳遞給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)機(ji)構的(de)(de)稱液壓制(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)(tie)(tie)(tie)。

閥用電磁鐵

供遠距離(li)操作(zuo)(zuo)(zuo)各種液壓(ya)(ya)、氣動(dong)(dong)系統閥(fa)門的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵。常用(yong)于各種金屬切削(xue)機床中(zhong)。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵不設(she)復(fu)位裝置，而由閥(fa)體中(zhong)的(de)彈(dan)簧使(shi)(shi)之復(fu)位。當電(dian)(dian)磁(ci)(ci)(ci)鐵的(de)勵(li)磁(ci)(ci)(ci)繞組通過電(dian)(dian)流時，電(dian)(dian)磁(ci)(ci)(ci)吸(xi)力即(ji)克服彈(dan)簧阻(zu)力，使(shi)(shi)閥(fa)體的(de)推桿移動(dong)(dong)，將閥(fa)門開啟;當勵(li)磁(ci)(ci)(ci)繞組斷電(dian)(dian)后，在復(fu)位彈(dan)簧作(zuo)(zuo)(zuo)用(yong)下，閥(fa)體推桿便(bian)推動(dong)(dong)銜鐵，使(shi)(shi)其(qi)(qi)移動(dong)(dong)額(e)定行程處，閥(fa)門關閉。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵分為濕(shi)式和干式兩(liang)種。濕(shi)式閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵的(de)銜鐵在液壓(ya)(ya)油中(zhong)工作(zuo)(zuo)(zuo)，由于油的(de)冷卻作(zuo)(zuo)(zuo)用(yong)，使(shi)(shi)其(qi)(qi)與具有(you)(you)相同吸(xi)力的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵相比，有(you)(you)較小(xiao)的(de)尺寸。

電磁鐵的應用

門(men)(men)(men)禁：為什(shen)么(me)門(men)(men)(men)禁可以在(zai)沒(mei)刷卡時把門(men)(men)(men)牢(lao)牢(lao)的“抓住(zhu)”？原(yuan)來單(dan)元(yuan)門(men)(men)(men)是由(you)鋼材料做成的，那(nei)個金屬體在(zai)通電(dian)(dian)時可以產(chan)生(sheng)強大的磁場(chang)，產(chan)生(sheng)的磁力(li)能把門(men)(men)(men)牢(lao)牢(lao)的吸住(zhu)，而(er)刷卡的瞬間，切(qie)斷電(dian)(dian)流，金屬體失(shi)去(qu)磁性(xing)，我(wo)們(men)就可以打開門(men)(men)(men)了。那(nei)個金屬體其實是一塊電(dian)(dian)磁鐵(tie)。

電(dian)(dian)磁(ci)(ci)起(qi)重(zhong)(zhong)機(ji)(ji)：最直接的應用之一(yi)(yi)是電(dian)(dian)磁(ci)(ci)起(qi)重(zhong)(zhong)機(ji)(ji)。電(dian)(dian)磁(ci)(ci)鐵安裝在吊(diao)車上，通電(dian)(dian)后吸起(qi)大(da)量鋼(gang)鐵，移動到(dao)另一(yi)(yi)個位置后切斷電(dian)(dian)流，鋼(gang)鐵被放下，免去了打捆的麻(ma)煩。大(da)型電(dian)(dian)磁(ci)(ci)起(qi)重(zhong)(zhong)機(ji)(ji)一(yi)(yi)次可以吊(diao)起(qi)幾噸鋼(gang)材。

在電(dian)動機、發電(dian)機、電(dian)鈴和(he)電(dian)磁繼電(dian)器里也(ye)用(yong)到電(dian)磁鐵。全自動洗衣機的(de)進水、排水閥(fa)門(men)，衛生間(jian)里感應(ying)式沖水器的(de)閥(fa)門(men)，也(ye)都是由(you)電(dian)磁鐵控(kong)制(zhi)的(de)。

電(dian)磁(ci)鐵(tie)的另一(yi)個應用是產生強磁(ci)場。現代技術中很(hen)多地(di)方需(xu)要的強磁(ci)場都(dou)由電(dian)磁(ci)鐵(tie)提(ti)供，如大型電(dian)動機、發電(dian)機、磁(ci)療(liao)設備等(deng)。