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。這實際上是南京電磁鐵原(yuan)理的(de)(de)(de)最初發現。1823年，斯特金也(ye)做了(le)一次類(lei)似(si)的(de)(de)(de)實驗：他在一根并非是磁(ci)(ci)鐵(tie)棒(bang)(bang)的(de)(de)(de)U型鐵(tie)棒(bang)(bang)上繞了(le)18圈銅(tong)裸線，當銅(tong)線與伏打(da)電(dian)(dian)池(chi)接通(tong)時(shi)，繞在U型鐵(tie)棒(bang)(bang)上的(de)(de)(de)銅(tong)線圈即(ji)產生了(le)密集(ji)的(de)(de)(de)磁(ci)(ci)場，這樣(yang)就(jiu)使(shi)U型鐵(tie)棒(bang)(bang)變成了(le)一塊“電(dian)(dian)磁(ci)(ci)鐵(tie)”。這種電(dian)(dian)磁(ci)(ci)鐵(tie)上的(de)(de)(de)磁(ci)(ci)能要比(bi)永磁(ci)(ci)能大放多(duo)倍(bei)，它(ta)能吸起比(bi)它(ta)重(zhong)20倍(bei)的(de)(de)(de)鐵(tie)塊，而當電(dian)(dian)源(yuan)切斷(duan)后，U型鐵(tie)棒(bang)(bang)就(jiu)什么鐵(tie)塊也(ye)吸不住，重(zhong)新(xin)成為一根普通(tong)的(de)(de)(de)鐵(tie)棒(bang)(bang)。

斯特(te)金的電(dian)磁鐵發明(ming)(ming)，使人們看到了把電(dian)能轉化為磁能的光(guang)明(ming)(ming)前(qian)景，這一發明(ming)(ming)很快在英國(guo)、美國(guo)以及西歐一些沿海(hai)國(guo)家傳(chuan)播開來(lai)。

1829年，美國電學(xue)家亨利(li)對斯特(te)金電磁(ci)(ci)鐵裝置進(jin)行了(le)一些革新，絕緣(yuan)導(dao)(dao)線(xian)(xian)代替裸銅導(dao)(dao)線(xian)(xian)，因此不必擔心被銅導(dao)(dao)線(xian)(xian)過分靠(kao)近而短路。由于導(dao)(dao)線(xian)(xian)有了(le)絕緣(yuan)層，就可以(yi)將(jiang)它們一圈圈地緊緊地繞在一起(qi)，由于線(xian)(xian)圈越(yue)密集，產生的(de)(de)(de)磁(ci)(ci)場就越(yue)強，這樣就大大提(ti)高了(le)把(ba)電能轉化(hua)為磁(ci)(ci)能的(de)(de)(de)能力(li)。到了(le)1831年，亨利(li)試制(zhi)出了(le)一塊(kuai)(kuai)更(geng)新的(de)(de)(de)電磁(ci)(ci)鐵，雖然它的(de)(de)(de)體積并不大，但(dan)它能吸起(qi)1噸重的(de)(de)(de)鐵塊(kuai)(kuai)。

電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)內部帶有(you)鐵(tie)(tie)(tie)心的、利用通(tong)有(you)電(dian)(dian)(dian)流的線圈(quan)使(shi)其像磁(ci)(ci)鐵(tie)(tie)(tie)一樣具有(you)磁(ci)(ci)性(xing)的裝置叫做電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)，通(tong)常制成條形或(huo)(huo)蹄形。鐵(tie)(tie)(tie)心要用容易(yi)磁(ci)(ci)化(hua)，又容易(yi)消(xiao)(xiao)失磁(ci)(ci)性(xing)的軟鐵(tie)(tie)(tie)或(huo)(huo)硅(gui)鋼來制做。這樣的電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)在通(tong)電(dian)(dian)(dian)時有(you)磁(ci)(ci)性(xing)，斷電(dian)(dian)(dian)后就隨之消(xiao)(xiao)失。 電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)有(you)許多(duo)優點(dian)：電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)磁(ci)(ci)性(xing)的有(you)無，可以(yi)用通(tong)、斷電(dian)(dian)(dian)流控(kong)制。磁(ci)(ci)性(xing)的大小(xiao)可以(yi)用電(dian)(dian)(dian)流的強弱或(huo)(huo)線圈(quan)的匝數(shu)來控(kong)制。

電磁鐵的主要特點

1、采用全密(mi)封結構，防潮性能好。

2、經計算機優化設計，結構合理、自重輕、吸力大、能耗低。

3、勵(li)磁線圈經特(te)別(bie)工藝(yi)處理，提高了線圈的電器和機械性能，絕(jue)緣資料(liao)熱(re)等級(ji)到達C級(ji)，運用壽命長。

4、普(pu)通型電(dian)磁鐵的(de)額定通電(dian)持(chi)續率由曩昔的(de)50%提高到60%，提高了電(dian)磁鐵的(de)運用功率。

5、超高(gao)溫(wen)型(xing)電(dian)磁鐵采用獨特隔熱方式，其間被吸物溫(wen)度有(you)曩昔的600℃提高(gao)700℃，擴大了電(dian)磁鐵的適(shi)用范圍。

6、裝(zhuang)置、運轉、保護簡潔。

電磁鐵工作原理

將(jiang)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)能變(bian)換為機(ji)械(xie)能以實現吸(xi)(xi)合(he)作(zuo)(zuo)功的一種電(dian)(dian)(dian)(dian)器。通(tong)常由軟磁(ci)(ci)(ci)(ci)材料制成的鐵(tie)心、銜(xian)鐵(tie)和(he)勵(li)磁(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)組(zu)(zu)成。當勵(li)磁(ci)(ci)(ci)(ci)繞(rao)組(zu)(zu)通(tong)電(dian)(dian)(dian)(dian)時，繞(rao)組(zu)(zu)周圍產(chan)生(sheng)磁(ci)(ci)(ci)(ci)場，鐵(tie)心磁(ci)(ci)(ci)(ci)化，并產(chan)生(sheng)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)銜(xian)鐵(tie)，使之運(yun)動作(zuo)(zuo)功。電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)主要用于(yu)操(cao)動、牽(qian)引(yin)機(ji)械(xie)裝置，以達到預(yu)期的目的。工業上常用的電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)有(you)制動電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)、牽(qian)引(yin)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)、起重(zhong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)和(he)閥(fa)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)等。此外，屬于(yu)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)類的還有(you)用以傳(chuan)遞或(huo)隔斷(duan)兩(liang)軸間的機(ji)械(xie)聯(lian)系的電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)聯(lian)軸器;用在機(ji)床工作(zuo)(zuo)臺上以吸(xi)(xi)牢磁(ci)(ci)(ci)(ci)性(xing)材料工件的電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)盤(pan);供高能物理(li)、核聚變(bian)研究、磁(ci)(ci)(ci)(ci)流(liu)體發電(dian)(dian)(dian)(dian)和(he)高速(su)懸浮列車等方面使用的、能產(chan)生(sheng)高達數十(shi)特（斯拉）的磁(ci)(ci)(ci)(ci)通(tong)密度而(er)幾乎不消耗繞(rao)組(zu)(zu)功率的超導電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)等。

起重電磁鐵

用(yong)來(lai)吊運(yun)和(he)裝卸鐵磁(ci)(ci)性物體(ti)的(de)電磁(ci)(ci)鐵。工業(ye)上常(chang)用(yong)以(yi)(yi)吊運(yun)或(huo)(huo)裝卸鐵礦石、鐵砂、廢鋼鐵、鋼錠、鋼軌以(yi)(yi)及各種鋼材(cai)和(he)鋼質工件。起(qi)重(zhong)電磁(ci)(ci)鐵通(tong)常(chang)做(zuo)成圓盤(pan)形或(huo)(huo)矩形，并帶有內磁(ci)(ci)極(ji)和(he)外(wai)磁(ci)(ci)極(ji)。當勵(li)磁(ci)(ci)繞組(zu)通(tong)電后，內外(wai)磁(ci)(ci)極(ji)均被磁(ci)(ci)化，吸引鋼質材(cai)料或(huo)(huo)工件（相(xiang)當于一般電磁(ci)(ci)鐵中的(de)銜鐵），形成一個閉合的(de)磁(ci)(ci)路。為保護勵(li)磁(ci)(ci)繞組(zu)，使之(zhi)不因磁(ci)(ci)極(ji)與被吸引物體(ti)間(jian)的(de)機械(xie)撞擊(ji)所(suo)損傷(shang)，起(qi)重(zhong)電磁(ci)(ci)鐵通(tong)常(chang)采用(yong)甲殼(ke)式結構，并且采用(yong)直流勵(li)磁(ci)(ci)。

牽引電磁鐵

供(gong)牽(qian)(qian)引和推斥機械裝(zhuang)置(zhi)用(yong)(yong)的(de)一種電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)。主要用(yong)(yong)于各種自動(dong)(dong)設備(bei)中，以實現遠距離控制。為了(le)能夠在長行(xing)程下獲得較大的(de)電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)，牽(qian)(qian)引電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)一般采用(yong)(yong)吸(xi)(xi)引特(te)性比較平(ping)坦的(de)甲殼式結構。其內部裝(zhuang)有鐵(tie)(tie)心、銜(xian)(xian)鐵(tie)(tie)和勵(li)磁(ci)(ci)(ci)(ci)線圈。使(shi)用(yong)(yong)時，將鐵(tie)(tie)心固定在機械裝(zhuang)置(zhi)的(de)靜止部件上，銜(xian)(xian)鐵(tie)(tie)則連接在牽(qian)(qian)引桿(gan)上。當勵(li)磁(ci)(ci)(ci)(ci)繞組(zu)通(tong)電(dian)后，鐵(tie)(tie)心被磁(ci)(ci)(ci)(ci)化，產生電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)吸(xi)(xi)引銜(xian)(xian)鐵(tie)(tie)，后者(zhe)則通(tong)過牽(qian)(qian)引桿(gan)來操(cao)縱所控制的(de)機械裝(zhuang)置(zhi)的(de)機構。為了(le)適應(ying)不同控制對象的(de)需要，牽(qian)(qian)引電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有拉動(dong)(dong)式和推動(dong)(dong)式兩種，但都不具(ju)備(bei)復(fu)位(wei)裝(zhuang)置(zhi)。牽(qian)(qian)引電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)的(de)主要技術(shu)指標為一定行(xing)程下的(de)電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)、操(cao)作頻(pin)率和壽命。

制動電磁鐵

作機(ji)械制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)用(yong)(yong)的(de)(de)一(yi)(yi)種電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。主要用(yong)(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)裝置和(he)起重運(yun)輸設備中，并與(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)配合使用(yong)(yong)，使電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)準(zhun)確停(ting)車和(he)懸吊著(zhu)的(de)(de)重物不(bu)致墜(zhui)落。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)按銜鐵(tie)(tie)(tie)行(xing)(xing)程分(fen)(fen)為(wei)長(chang)行(xing)(xing)程和(he)短(duan)行(xing)(xing)程兩類(lei);按勵磁(ci)(ci)(ci)方(fang)式分(fen)(fen)為(wei)直流和(he)交(jiao)流、并勵和(he)串勵以及單相(xiang)和(he)三(san)相(xiang)等種類(lei)。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)工作原理是(shi)(shi)：當電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)繞(rao)組(zu)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)后，銜鐵(tie)(tie)(tie)被(bei)吸向鐵(tie)(tie)(tie)心，并通(tong)(tong)過制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)中的(de)(de)停(ting)檔壓迫制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿，使之(zhi)移動(dong)(dong)(dong)，從而(er)(er)迫使制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)松閘。切斷線(xian)圈電(dian)(dian)(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿在(zai)彈簧(huang)作用(yong)(yong)下使銜鐵(tie)(tie)(tie)脫離磁(ci)(ci)(ci)軛(e)，而(er)(er)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)則將(jiang)機(ji)構剎住。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)主要技術參數(shu)是(shi)(shi)行(xing)(xing)程、一(yi)(yi)定行(xing)(xing)程下的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸力、操作頻率和(he)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)(xu)率。操作頻率是(shi)(shi)指每小時(shi)(shi)操作的(de)(de)次數(shu);通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)(xu)率是(shi)(shi)指每次通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間與(yu)每次通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)及不(bu)通(tong)(tong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間之(zhi)和(he)的(de)(de)百分(fen)(fen)比。使用(yong)(yong)中，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)與(yu)瓦式制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)相(xiang)配合時(shi)(shi)用(yong)(yong)短(duan)行(xing)(xing)程類(lei);與(yu)皮帶(dai)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器(qi)(qi)(qi)(qi)相(xiang)配合時(shi)(shi)用(yong)(yong)長(chang)行(xing)(xing)程類(lei)。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通(tong)(tong)過液壓方(fang)式將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)力傳遞給制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)機(ji)構的(de)(de)稱液壓制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。

閥用電磁鐵

供遠距離操作(zuo)各種液(ye)壓、氣動系統閥門的(de)電(dian)磁(ci)鐵(tie)(tie)(tie)。常用于(yu)各種金屬切削機床中(zhong)。閥用電(dian)磁(ci)鐵(tie)(tie)(tie)不設復位(wei)裝(zhuang)置，而由(you)閥體(ti)中(zhong)的(de)彈簧使(shi)之復位(wei)。當(dang)電(dian)磁(ci)鐵(tie)(tie)(tie)的(de)勵磁(ci)繞組通過電(dian)流時，電(dian)磁(ci)吸(xi)力(li)(li)(li)即(ji)克服彈簧阻力(li)(li)(li)，使(shi)閥體(ti)的(de)推(tui)桿(gan)移動，將閥門開(kai)啟;當(dang)勵磁(ci)繞組斷電(dian)后，在復位(wei)彈簧作(zuo)用下，閥體(ti)推(tui)桿(gan)便(bian)推(tui)動銜鐵(tie)(tie)(tie)，使(shi)其移動額定行程處(chu)，閥門關閉。閥用電(dian)磁(ci)鐵(tie)(tie)(tie)分為濕式(shi)(shi)和(he)干式(shi)(shi)兩種。濕式(shi)(shi)閥用電(dian)磁(ci)鐵(tie)(tie)(tie)的(de)銜鐵(tie)(tie)(tie)在液(ye)壓油(you)(you)中(zhong)工作(zuo)，由(you)于(yu)油(you)(you)的(de)冷卻作(zuo)用，使(shi)其與具有相同吸(xi)力(li)(li)(li)的(de)電(dian)磁(ci)鐵(tie)(tie)(tie)相比，有較(jiao)小的(de)尺寸。

電磁鐵的應用

門(men)(men)禁：為(wei)什么門(men)(men)禁可以(yi)在(zai)沒(mei)刷(shua)卡時把門(men)(men)牢牢的(de)“抓住”？原來單元(yuan)門(men)(men)是由鋼材料做成的(de)，那(nei)個金屬(shu)體在(zai)通電時可以(yi)產生強大的(de)磁場(chang)，產生的(de)磁力(li)能把門(men)(men)牢牢的(de)吸住，而刷(shua)卡的(de)瞬間，切斷電流，金屬(shu)體失去磁性(xing)，我們就(jiu)可以(yi)打開門(men)(men)了。那(nei)個金屬(shu)體其實是一塊電磁鐵。

電磁(ci)起重機：最直接的(de)應用之一(yi)是電磁(ci)起重機。電磁(ci)鐵安裝在吊車上，通電后吸起大量鋼(gang)鐵，移動到(dao)另一(yi)個位置(zhi)后切斷電流，鋼(gang)鐵被放(fang)下，免(mian)去(qu)了打捆的(de)麻煩。大型電磁(ci)起重機一(yi)次可以(yi)吊起幾噸鋼(gang)材。

在電(dian)動機、發電(dian)機、電(dian)鈴和電(dian)磁(ci)(ci)繼電(dian)器(qi)里也用(yong)到電(dian)磁(ci)(ci)鐵(tie)。全自動洗衣機的進水(shui)、排水(shui)閥(fa)(fa)門，衛生間里感應式沖水(shui)器(qi)的閥(fa)(fa)門，也都(dou)是(shi)由電(dian)磁(ci)(ci)鐵(tie)控(kong)制的。

電(dian)磁鐵的另一個應用是產(chan)生強磁場。現(xian)代技術中很多地方需要(yao)的強磁場都由電(dian)磁鐵提供，如大型電(dian)動(dong)機、發電(dian)機、磁療設備等。