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。這實際上是上海電磁鐵原(yuan)理的(de)最(zui)初發現。1823年(nian)，斯(si)特金(jin)也做了一次(ci)類似的(de)實驗：他在一根并非(fei)是磁(ci)(ci)鐵(tie)(tie)棒(bang)(bang)的(de)U型(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)繞(rao)了18圈(quan)銅裸線(xian)，當(dang)(dang)銅線(xian)與(yu)伏打電池接(jie)通時，繞(rao)在U型(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)的(de)銅線(xian)圈(quan)即產(chan)生了密集(ji)的(de)磁(ci)(ci)場，這樣就(jiu)使U型(xing)鐵(tie)(tie)棒(bang)(bang)變成了一塊“電磁(ci)(ci)鐵(tie)(tie)”。這種電磁(ci)(ci)鐵(tie)(tie)上(shang)的(de)磁(ci)(ci)能要(yao)比永磁(ci)(ci)能大(da)放多(duo)倍，它能吸起比它重(zhong)20倍的(de)鐵(tie)(tie)塊，而(er)當(dang)(dang)電源切斷后，U型(xing)鐵(tie)(tie)棒(bang)(bang)就(jiu)什(shen)么鐵(tie)(tie)塊也吸不住，重(zhong)新成為一根普通的(de)鐵(tie)(tie)棒(bang)(bang)。

斯特金的(de)電磁(ci)鐵發明，使人們看到了把電能(neng)轉化為磁(ci)能(neng)的(de)光明前景，這一發明很快在英國(guo)、美國(guo)以及西(xi)歐一些沿海國(guo)家傳播開來。

1829年，美國電(dian)(dian)學(xue)家亨(heng)利對斯特金電(dian)(dian)磁(ci)鐵裝(zhuang)置(zhi)進(jin)行了一些革新，絕緣導(dao)(dao)線(xian)代替裸銅導(dao)(dao)線(xian)，因(yin)此不必擔心被銅導(dao)(dao)線(xian)過分(fen)靠(kao)近而短路。由(you)于(yu)導(dao)(dao)線(xian)有了絕緣層，就(jiu)可(ke)以將它們一圈圈地緊緊地繞在一起，由(you)于(yu)線(xian)圈越(yue)密集(ji)，產生的(de)磁(ci)場就(jiu)越(yue)強，這樣(yang)就(jiu)大大提高了把電(dian)(dian)能轉化(hua)為磁(ci)能的(de)能力。到了1831年，亨(heng)利試制出了一塊更新的(de)電(dian)(dian)磁(ci)鐵，雖(sui)然(ran)它的(de)體積并不大，但它能吸起1噸重的(de)鐵塊。

電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)內部帶有(you)鐵(tie)(tie)心(xin)的(de)(de)、利用通(tong)(tong)有(you)電(dian)(dian)(dian)流(liu)(liu)的(de)(de)線圈(quan)使其像(xiang)磁(ci)(ci)鐵(tie)(tie)一樣具有(you)磁(ci)(ci)性(xing)(xing)的(de)(de)裝置(zhi)叫做電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)，通(tong)(tong)常制(zhi)(zhi)成(cheng)條形(xing)或蹄形(xing)。鐵(tie)(tie)心(xin)要用容(rong)易(yi)磁(ci)(ci)化，又容(rong)易(yi)消(xiao)失(shi)磁(ci)(ci)性(xing)(xing)的(de)(de)軟鐵(tie)(tie)或硅鋼(gang)來制(zhi)(zhi)做。這樣的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)在通(tong)(tong)電(dian)(dian)(dian)時有(you)磁(ci)(ci)性(xing)(xing)，斷(duan)(duan)電(dian)(dian)(dian)后就隨(sui)之消(xiao)失(shi)。 電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)有(you)許(xu)多優點：電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)磁(ci)(ci)性(xing)(xing)的(de)(de)有(you)無，可以用通(tong)(tong)、斷(duan)(duan)電(dian)(dian)(dian)流(liu)(liu)控制(zhi)(zhi)。磁(ci)(ci)性(xing)(xing)的(de)(de)大小可以用電(dian)(dian)(dian)流(liu)(liu)的(de)(de)強(qiang)弱或線圈(quan)的(de)(de)匝數(shu)來控制(zhi)(zhi)。

電磁鐵的主要特點

1、采用(yong)全密(mi)封結(jie)構，防潮性能(neng)好。

2、經計算機優化設計，結構合理(li)、自重輕、吸力(li)大、能耗低。

3、勵磁線圈(quan)經(jing)特別工藝處理，提高了線圈(quan)的電(dian)器(qi)和機械性能(neng)，絕緣資料熱等級(ji)到達C級(ji)，運用(yong)壽命長。

4、普通(tong)型電磁鐵(tie)的(de)(de)額定(ding)通(tong)電持續率(lv)(lv)由曩昔(xi)的(de)(de)50%提高到60%，提高了(le)電磁鐵(tie)的(de)(de)運用(yong)功率(lv)(lv)。

5、超高(gao)溫型電(dian)磁鐵(tie)采(cai)用獨特隔(ge)熱方式，其間被吸物溫度(du)有曩昔(xi)的600℃提高(gao)700℃，擴大了電(dian)磁鐵(tie)的適用范圍。

6、裝(zhuang)置(zhi)、運轉、保護簡潔(jie)。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)能變換(huan)為(wei)機械能以(yi)實現(xian)吸(xi)合作功的(de)(de)(de)(de)一種電(dian)(dian)(dian)器。通(tong)常由(you)軟(ruan)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)材料制成的(de)(de)(de)(de)鐵(tie)心、銜鐵(tie)和勵磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)繞(rao)(rao)組(zu)(zu)組(zu)(zu)成。當(dang)勵磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)繞(rao)(rao)組(zu)(zu)通(tong)電(dian)(dian)(dian)時，繞(rao)(rao)組(zu)(zu)周圍產生磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)場(chang)，鐵(tie)心磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)化，并產生電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)力吸(xi)引銜鐵(tie)，使之運動作功。電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)主要用于操動、牽(qian)引機械裝置(zhi)，以(yi)達到預期(qi)的(de)(de)(de)(de)目的(de)(de)(de)(de)。工(gong)(gong)業(ye)上常用的(de)(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)有制動電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)、牽(qian)引電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)、起重電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)和閥用電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)等(deng)。此外，屬(shu)于電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)類的(de)(de)(de)(de)還有用以(yi)傳遞或(huo)隔(ge)斷兩軸(zhou)間(jian)的(de)(de)(de)(de)機械聯(lian)系的(de)(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)聯(lian)軸(zhou)器;用在機床(chuang)工(gong)(gong)作臺上以(yi)吸(xi)牢磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)性材料工(gong)(gong)件的(de)(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)盤(pan);供高能物理、核聚變研究、磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)流(liu)體(ti)發(fa)電(dian)(dian)(dian)和高速(su)懸浮列車(che)等(deng)方面使用的(de)(de)(de)(de)、能產生高達數十特（斯拉(la)）的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)通(tong)密度而幾乎不消耗繞(rao)(rao)組(zu)(zu)功率的(de)(de)(de)(de)超導(dao)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)等(deng)。

起重電磁鐵

用(yong)來吊運和(he)裝(zhuang)卸鐵磁(ci)性物(wu)體的(de)電(dian)磁(ci)鐵。工(gong)(gong)業上(shang)常(chang)用(yong)以(yi)吊運或裝(zhuang)卸鐵礦(kuang)石、鐵砂、廢鋼(gang)(gang)(gang)鐵、鋼(gang)(gang)(gang)錠、鋼(gang)(gang)(gang)軌(gui)以(yi)及各種(zhong)鋼(gang)(gang)(gang)材(cai)和(he)鋼(gang)(gang)(gang)質(zhi)工(gong)(gong)件(jian)。起(qi)重電(dian)磁(ci)鐵通常(chang)做成圓盤形(xing)或矩形(xing)，并帶有內磁(ci)極和(he)外磁(ci)極。當勵(li)(li)磁(ci)繞(rao)組(zu)通電(dian)后，內外磁(ci)極均被磁(ci)化，吸引(yin)(yin)鋼(gang)(gang)(gang)質(zhi)材(cai)料或工(gong)(gong)件(jian)（相當于一般電(dian)磁(ci)鐵中(zhong)的(de)銜鐵），形(xing)成一個閉合的(de)磁(ci)路。為保(bao)護勵(li)(li)磁(ci)繞(rao)組(zu)，使之不(bu)因磁(ci)極與被吸引(yin)(yin)物(wu)體間的(de)機械撞擊所損傷，起(qi)重電(dian)磁(ci)鐵通常(chang)采(cai)用(yong)甲殼(ke)式(shi)結構，并且采(cai)用(yong)直流勵(li)(li)磁(ci)。

牽引電磁鐵

供(gong)牽引和推斥機(ji)(ji)械(xie)裝(zhuang)(zhuang)(zhuang)置用的一種(zhong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。主(zhu)要(yao)(yao)用于各(ge)種(zhong)自動(dong)設備(bei)中(zhong)，以(yi)實現遠距離控(kong)制。為(wei)了能(neng)夠在長行程下(xia)獲得較大的電(dian)磁(ci)(ci)吸(xi)(xi)力，牽引電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)一般(ban)采(cai)用吸(xi)(xi)引特性比(bi)較平坦(tan)的甲殼式(shi)結構。其內部(bu)(bu)裝(zhuang)(zhuang)(zhuang)有鐵(tie)(tie)(tie)心(xin)、銜(xian)鐵(tie)(tie)(tie)和勵磁(ci)(ci)線圈。使用時，將鐵(tie)(tie)(tie)心(xin)固定在機(ji)(ji)械(xie)裝(zhuang)(zhuang)(zhuang)置的靜(jing)止部(bu)(bu)件上(shang)，銜(xian)鐵(tie)(tie)(tie)則(ze)連接(jie)在牽引桿(gan)上(shang)。當勵磁(ci)(ci)繞組(zu)通電(dian)后，鐵(tie)(tie)(tie)心(xin)被磁(ci)(ci)化，產(chan)生電(dian)磁(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引銜(xian)鐵(tie)(tie)(tie)，后者則(ze)通過牽引桿(gan)來(lai)操縱所控(kong)制的機(ji)(ji)械(xie)裝(zhuang)(zhuang)(zhuang)置的機(ji)(ji)構。為(wei)了適應不(bu)同(tong)控(kong)制對象(xiang)的需(xu)要(yao)(yao)，牽引電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)有拉動(dong)式(shi)和推動(dong)式(shi)兩種(zhong)，但都(dou)不(bu)具備(bei)復位裝(zhuang)(zhuang)(zhuang)置。牽引電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的主(zhu)要(yao)(yao)技術(shu)指標為(wei)一定行程下(xia)的電(dian)磁(ci)(ci)吸(xi)(xi)力、操作(zuo)頻(pin)率和壽命(ming)。

制動電磁鐵

作(zuo)(zuo)機(ji)械制(zhi)(zhi)動(dong)(dong)用(yong)(yong)(yong)的一種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。主(zhu)要用(yong)(yong)(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)裝(zhuang)置和起重(zhong)運輸(shu)設備中，并與(yu)制(zhi)(zhi)動(dong)(dong)器(qi)配合(he)使(shi)用(yong)(yong)(yong)，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)準(zhun)確停(ting)車和懸吊著的重(zhong)物不致(zhi)墜落(luo)。制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)按銜鐵(tie)行(xing)程(cheng)分為長(chang)行(xing)程(cheng)和短行(xing)程(cheng)兩類(lei);按勵磁(ci)(ci)(ci)方(fang)式分為直(zhi)流(liu)和交流(liu)、并勵和串(chuan)勵以及單相(xiang)和三相(xiang)等種(zhong)類(lei)。制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的工作(zuo)(zuo)原理是(shi)：當電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的繞組通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)后，銜鐵(tie)被吸向鐵(tie)心，并通(tong)過制(zhi)(zhi)動(dong)(dong)器(qi)中的停(ting)檔(dang)壓迫(po)制(zhi)(zhi)動(dong)(dong)桿，使(shi)之移動(dong)(dong)，從而迫(po)使(shi)制(zhi)(zhi)動(dong)(dong)器(qi)松閘。切斷線圈電(dian)(dian)(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)動(dong)(dong)桿在彈簧作(zuo)(zuo)用(yong)(yong)(yong)下使(shi)銜鐵(tie)脫離磁(ci)(ci)(ci)軛，而制(zhi)(zhi)動(dong)(dong)器(qi)則將(jiang)機(ji)構(gou)剎住。制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的主(zhu)要技術(shu)參數(shu)是(shi)行(xing)程(cheng)、一定行(xing)程(cheng)下的電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸力、操(cao)作(zuo)(zuo)頻率和通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持續率。操(cao)作(zuo)(zuo)頻率是(shi)指每(mei)(mei)小時(shi)操(cao)作(zuo)(zuo)的次數(shu);通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持續率是(shi)指每(mei)(mei)次通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間與(yu)每(mei)(mei)次通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)及不通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間之和的百分比。使(shi)用(yong)(yong)(yong)中，制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)與(yu)瓦式制(zhi)(zhi)動(dong)(dong)器(qi)相(xiang)配合(he)時(shi)用(yong)(yong)(yong)短行(xing)程(cheng)類(lei);與(yu)皮帶制(zhi)(zhi)動(dong)(dong)器(qi)相(xiang)配合(he)時(shi)用(yong)(yong)(yong)長(chang)行(xing)程(cheng)類(lei)。制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)過液壓方(fang)式將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)力傳遞給(gei)制(zhi)(zhi)動(dong)(dong)機(ji)構(gou)的稱液壓制(zhi)(zhi)動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。

閥用電磁鐵

供(gong)遠距(ju)離操作各(ge)種液壓、氣動(dong)系統閥門的(de)(de)電(dian)磁(ci)(ci)鐵。常用(yong)于各(ge)種金屬(shu)切(qie)削機(ji)床(chuang)中。閥用(yong)電(dian)磁(ci)(ci)鐵不設復(fu)位(wei)裝(zhuang)置，而由(you)閥體中的(de)(de)彈簧(huang)使之復(fu)位(wei)。當電(dian)磁(ci)(ci)鐵的(de)(de)勵磁(ci)(ci)繞組(zu)通(tong)過電(dian)流時，電(dian)磁(ci)(ci)吸力(li)即克服彈簧(huang)阻力(li)，使閥體的(de)(de)推(tui)(tui)桿(gan)移動(dong)，將閥門開啟;當勵磁(ci)(ci)繞組(zu)斷電(dian)后，在復(fu)位(wei)彈簧(huang)作用(yong)下，閥體推(tui)(tui)桿(gan)便推(tui)(tui)動(dong)銜(xian)鐵，使其移動(dong)額定行程(cheng)處，閥門關閉。閥用(yong)電(dian)磁(ci)(ci)鐵分為濕(shi)式和干式兩種。濕(shi)式閥用(yong)電(dian)磁(ci)(ci)鐵的(de)(de)銜(xian)鐵在液壓油中工(gong)作，由(you)于油的(de)(de)冷卻(que)作用(yong)，使其與具有相(xiang)同(tong)吸力(li)的(de)(de)電(dian)磁(ci)(ci)鐵相(xiang)比，有較小的(de)(de)尺寸。

電磁鐵的應用

門禁(jin)：為什么(me)門禁(jin)可以(yi)在沒刷卡時(shi)把門牢(lao)(lao)牢(lao)(lao)的(de)“抓住(zhu)”？原來單元門是(shi)由鋼(gang)材料(liao)做成的(de)，那個金(jin)屬體(ti)(ti)在通電時(shi)可以(yi)產生強大的(de)磁(ci)(ci)(ci)場，產生的(de)磁(ci)(ci)(ci)力能把門牢(lao)(lao)牢(lao)(lao)的(de)吸住(zhu)，而刷卡的(de)瞬間，切斷(duan)電流，金(jin)屬體(ti)(ti)失去磁(ci)(ci)(ci)性，我(wo)們(men)就(jiu)可以(yi)打(da)開門了(le)。那個金(jin)屬體(ti)(ti)其實是(shi)一(yi)塊電磁(ci)(ci)(ci)鐵。

電磁(ci)(ci)(ci)起(qi)重機(ji)：最直接的應用之一(yi)是(shi)電磁(ci)(ci)(ci)起(qi)重機(ji)。電磁(ci)(ci)(ci)鐵安裝在(zai)吊車上，通電后吸(xi)起(qi)大量鋼鐵，移(yi)動到另一(yi)個位置后切斷電流，鋼鐵被(bei)放下，免(mian)去了打捆(kun)的麻煩。大型(xing)電磁(ci)(ci)(ci)起(qi)重機(ji)一(yi)次可(ke)以吊起(qi)幾噸鋼材(cai)。

在電(dian)動(dong)機、發電(dian)機、電(dian)鈴和電(dian)磁繼電(dian)器(qi)里也用(yong)到電(dian)磁鐵(tie)。全自動(dong)洗衣機的進水、排水閥門，衛生間里感(gan)應式沖水器(qi)的閥門，也都是由電(dian)磁鐵(tie)控(kong)制的。

電磁(ci)(ci)鐵的另一個應用是產(chan)生強磁(ci)(ci)場。現代技術中很多地方需要(yao)的強磁(ci)(ci)場都由電磁(ci)(ci)鐵提供，如大型電動機、發電機、磁(ci)(ci)療(liao)設備等。