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。這實際上是南昌電磁鐵原(yuan)理(li)的(de)最初(chu)發現(xian)。1823年，斯特金也(ye)做了(le)(le)(le)一次(ci)類(lei)似(si)的(de)實驗：他(ta)在一根并(bing)非是磁(ci)(ci)(ci)(ci)鐵(tie)(tie)棒(bang)的(de)U型(xing)鐵(tie)(tie)棒(bang)上(shang)繞了(le)(le)(le)18圈銅裸線(xian)，當銅線(xian)與伏打電(dian)(dian)池接通(tong)時，繞在U型(xing)鐵(tie)(tie)棒(bang)上(shang)的(de)銅線(xian)圈即產生了(le)(le)(le)密(mi)集的(de)磁(ci)(ci)(ci)(ci)場(chang)，這樣(yang)就使U型(xing)鐵(tie)(tie)棒(bang)變成(cheng)了(le)(le)(le)一塊(kuai)“電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)”。這種電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)上(shang)的(de)磁(ci)(ci)(ci)(ci)能(neng)(neng)要比永磁(ci)(ci)(ci)(ci)能(neng)(neng)大(da)放(fang)多(duo)倍(bei)，它(ta)能(neng)(neng)吸起(qi)比它(ta)重20倍(bei)的(de)鐵(tie)(tie)塊(kuai)，而當電(dian)(dian)源切(qie)斷后，U型(xing)鐵(tie)(tie)棒(bang)就什么(me)鐵(tie)(tie)塊(kuai)也(ye)吸不住，重新成(cheng)為(wei)一根普通(tong)的(de)鐵(tie)(tie)棒(bang)。

斯特金的電(dian)磁鐵發明，使人們(men)看到了把電(dian)能(neng)轉化(hua)為磁能(neng)的光(guang)明前景，這一(yi)發明很快(kuai)在(zai)英國(guo)、美國(guo)以及西(xi)歐(ou)一(yi)些沿海國(guo)家傳播開來。

1829年(nian)，美(mei)國電學(xue)家亨利(li)對斯特金電磁鐵裝(zhuang)置進(jin)行了(le)(le)一些革新(xin)，絕緣導(dao)(dao)線(xian)代替裸銅(tong)導(dao)(dao)線(xian)，因(yin)此不必擔心被(bei)銅(tong)導(dao)(dao)線(xian)過(guo)分(fen)靠近而短路。由(you)(you)于導(dao)(dao)線(xian)有(you)了(le)(le)絕緣層，就(jiu)可以將它們(men)一圈圈地(di)緊緊地(di)繞在一起，由(you)(you)于線(xian)圈越(yue)密集，產生的磁場(chang)就(jiu)越(yue)強(qiang)，這樣就(jiu)大(da)大(da)提高了(le)(le)把電能(neng)(neng)轉化為磁能(neng)(neng)的能(neng)(neng)力。到了(le)(le)1831年(nian)，亨利(li)試制出(chu)了(le)(le)一塊更新(xin)的電磁鐵，雖然它的體積并不大(da)，但它能(neng)(neng)吸(xi)起1噸重的鐵塊。

電(dian)(dian)磁(ci)(ci)鐵(tie)內部帶有(you)鐵(tie)心(xin)的(de)(de)(de)、利用(yong)(yong)通(tong)(tong)有(you)電(dian)(dian)流(liu)的(de)(de)(de)線(xian)圈使其像磁(ci)(ci)鐵(tie)一樣具有(you)磁(ci)(ci)性(xing)的(de)(de)(de)裝(zhuang)置叫做電(dian)(dian)磁(ci)(ci)鐵(tie)，通(tong)(tong)常(chang)制成(cheng)條形或(huo)蹄形。鐵(tie)心(xin)要(yao)用(yong)(yong)容(rong)易(yi)(yi)磁(ci)(ci)化，又容(rong)易(yi)(yi)消失磁(ci)(ci)性(xing)的(de)(de)(de)軟鐵(tie)或(huo)硅鋼來制做。這樣的(de)(de)(de)電(dian)(dian)磁(ci)(ci)鐵(tie)在通(tong)(tong)電(dian)(dian)時有(you)磁(ci)(ci)性(xing)，斷(duan)電(dian)(dian)后就隨之消失。 電(dian)(dian)磁(ci)(ci)鐵(tie)有(you)許多優點：電(dian)(dian)磁(ci)(ci)鐵(tie)磁(ci)(ci)性(xing)的(de)(de)(de)有(you)無，可以用(yong)(yong)通(tong)(tong)、斷(duan)電(dian)(dian)流(liu)控制。磁(ci)(ci)性(xing)的(de)(de)(de)大小(xiao)可以用(yong)(yong)電(dian)(dian)流(liu)的(de)(de)(de)強弱或(huo)線(xian)圈的(de)(de)(de)匝數來控制。

電磁鐵的主要特點

1、采用全密(mi)封(feng)結構，防(fang)潮性能好。

2、經計算機優(you)化設計，結(jie)構合理、自(zi)重(zhong)輕、吸(xi)力大、能(neng)耗低。

3、勵磁線(xian)圈經(jing)特別(bie)工藝處理(li)，提高了(le)線(xian)圈的電器和機械(xie)性能，絕緣資料熱等級到達(da)C級，運(yun)用壽命長。

4、普通(tong)(tong)型電磁鐵的(de)額定通(tong)(tong)電持續率(lv)由曩昔的(de)50%提高到60%，提高了電磁鐵的(de)運(yun)用(yong)功率(lv)。

5、超高溫(wen)型電磁(ci)鐵采用(yong)獨特隔熱方式(shi)，其間被吸物(wu)溫(wen)度有(you)曩昔的(de)600℃提高700℃，擴大了電磁(ci)鐵的(de)適用(yong)范圍。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將(jiang)電(dian)(dian)磁(ci)(ci)(ci)能變換為機(ji)(ji)械能以實現吸(xi)(xi)(xi)合(he)作(zuo)功的(de)(de)(de)(de)一種電(dian)(dian)器。通(tong)常由軟磁(ci)(ci)(ci)材(cai)料制(zhi)成的(de)(de)(de)(de)鐵(tie)(tie)(tie)(tie)心、銜鐵(tie)(tie)(tie)(tie)和(he)勵磁(ci)(ci)(ci)繞組組成。當勵磁(ci)(ci)(ci)繞組通(tong)電(dian)(dian)時(shi)，繞組周圍產生(sheng)磁(ci)(ci)(ci)場(chang)，鐵(tie)(tie)(tie)(tie)心磁(ci)(ci)(ci)化，并產生(sheng)電(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)(xi)力吸(xi)(xi)(xi)引銜鐵(tie)(tie)(tie)(tie)，使(shi)之運動作(zuo)功。電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)主(zhu)要用(yong)(yong)于操動、牽(qian)引機(ji)(ji)械裝(zhuang)置，以達(da)到(dao)預期(qi)的(de)(de)(de)(de)目的(de)(de)(de)(de)。工(gong)(gong)業(ye)上常用(yong)(yong)的(de)(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)有制(zhi)動電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)、牽(qian)引電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)、起重電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)和(he)閥(fa)用(yong)(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等。此外，屬(shu)于電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)類的(de)(de)(de)(de)還有用(yong)(yong)以傳遞或隔斷兩軸(zhou)(zhou)間的(de)(de)(de)(de)機(ji)(ji)械聯(lian)系的(de)(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)聯(lian)軸(zhou)(zhou)器;用(yong)(yong)在機(ji)(ji)床工(gong)(gong)作(zuo)臺上以吸(xi)(xi)(xi)牢磁(ci)(ci)(ci)性材(cai)料工(gong)(gong)件的(de)(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)(xi)盤;供高(gao)(gao)能物理(li)、核聚變研究、磁(ci)(ci)(ci)流體(ti)發(fa)電(dian)(dian)和(he)高(gao)(gao)速懸浮列車等方面使(shi)用(yong)(yong)的(de)(de)(de)(de)、能產生(sheng)高(gao)(gao)達(da)數十特（斯拉）的(de)(de)(de)(de)磁(ci)(ci)(ci)通(tong)密(mi)度而(er)幾乎不消耗(hao)繞組功率的(de)(de)(de)(de)超(chao)導電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等。

起重電磁鐵

用來吊(diao)運和(he)裝卸(xie)鐵(tie)磁性(xing)物(wu)體的(de)電(dian)磁鐵(tie)。工業上常(chang)用以吊(diao)運或裝卸(xie)鐵(tie)礦(kuang)石、鐵(tie)砂、廢鋼鐵(tie)、鋼錠、鋼軌(gui)以及各種鋼材和(he)鋼質工件(jian)(jian)。起(qi)重電(dian)磁鐵(tie)通常(chang)做成(cheng)圓盤(pan)形或矩形，并帶有內磁極(ji)和(he)外磁極(ji)。當(dang)勵磁繞(rao)組(zu)通電(dian)后，內外磁極(ji)均被(bei)磁化，吸引鋼質材料(liao)或工件(jian)(jian)（相當(dang)于一(yi)般電(dian)磁鐵(tie)中(zhong)的(de)銜鐵(tie)），形成(cheng)一(yi)個閉(bi)合(he)的(de)磁路(lu)。為保護(hu)勵磁繞(rao)組(zu)，使之不(bu)因磁極(ji)與被(bei)吸引物(wu)體間的(de)機械撞擊所(suo)損傷，起(qi)重電(dian)磁鐵(tie)通常(chang)采用甲殼式結構，并且采用直流勵磁。

牽引電磁鐵

供牽(qian)引(yin)(yin)(yin)和推(tui)斥機(ji)械裝(zhuang)置(zhi)(zhi)用的一種電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)。主(zhu)要用于(yu)各(ge)種自動設(she)備中，以實現遠(yuan)距離控(kong)(kong)制(zhi)。為(wei)了能夠在長行程下(xia)獲(huo)得(de)較大的電(dian)(dian)磁(ci)吸(xi)力(li)，牽(qian)引(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)一般采用吸(xi)引(yin)(yin)(yin)特(te)性(xing)比較平坦(tan)的甲殼式結(jie)構。其內部裝(zhuang)有(you)鐵(tie)(tie)(tie)心(xin)、銜(xian)鐵(tie)(tie)(tie)和勵磁(ci)線圈。使用時(shi)，將鐵(tie)(tie)(tie)心(xin)固定(ding)在機(ji)械裝(zhuang)置(zhi)(zhi)的靜(jing)止部件上，銜(xian)鐵(tie)(tie)(tie)則連接在牽(qian)引(yin)(yin)(yin)桿上。當(dang)勵磁(ci)繞組通電(dian)(dian)后(hou)，鐵(tie)(tie)(tie)心(xin)被磁(ci)化，產生電(dian)(dian)磁(ci)吸(xi)力(li)吸(xi)引(yin)(yin)(yin)銜(xian)鐵(tie)(tie)(tie)，后(hou)者則通過牽(qian)引(yin)(yin)(yin)桿來(lai)操縱所控(kong)(kong)制(zhi)的機(ji)械裝(zhuang)置(zhi)(zhi)的機(ji)構。為(wei)了適應不同(tong)控(kong)(kong)制(zhi)對(dui)象的需要，牽(qian)引(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)有(you)拉動式和推(tui)動式兩(liang)種，但都(dou)不具備復位裝(zhuang)置(zhi)(zhi)。牽(qian)引(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)的主(zhu)要技術(shu)指標為(wei)一定(ding)行程下(xia)的電(dian)(dian)磁(ci)吸(xi)力(li)、操作頻(pin)率和壽(shou)命。

制動電磁鐵

作(zuo)機(ji)(ji)(ji)械制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)用(yong)(yong)(yong)的(de)(de)一種電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵。主要用(yong)(yong)(yong)于電(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)起重運輸設備(bei)中(zhong)，并(bing)與(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配合(he)(he)使(shi)用(yong)(yong)(yong)，使(shi)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)準確停車和(he)(he)懸吊著的(de)(de)重物不(bu)致墜落。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵按(an)銜鐵行(xing)程分(fen)(fen)為(wei)長(chang)行(xing)程和(he)(he)短行(xing)程兩(liang)類(lei);按(an)勵(li)(li)磁(ci)(ci)方(fang)式(shi)(shi)分(fen)(fen)為(wei)直流(liu)和(he)(he)交(jiao)流(liu)、并(bing)勵(li)(li)和(he)(he)串(chuan)勵(li)(li)以(yi)及單相和(he)(he)三(san)相等種類(lei)。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵的(de)(de)工(gong)作(zuo)原理是：當電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵的(de)(de)繞組通(tong)電(dian)(dian)(dian)(dian)后(hou)，銜鐵被吸向鐵心，并(bing)通(tong)過制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中(zhong)的(de)(de)停檔壓迫(po)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)桿(gan)，使(shi)之移(yi)動(dong)(dong)(dong)(dong)(dong)(dong)，從而迫(po)使(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松閘。切(qie)斷線圈電(dian)(dian)(dian)(dian)源后(hou)，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)桿(gan)在彈簧作(zuo)用(yong)(yong)(yong)下(xia)使(shi)銜鐵脫離磁(ci)(ci)軛(e)，而制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則將機(ji)(ji)(ji)構剎住。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵的(de)(de)主要技術參數是行(xing)程、一定行(xing)程下(xia)的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)吸力、操(cao)作(zuo)頻(pin)率(lv)和(he)(he)通(tong)電(dian)(dian)(dian)(dian)持續率(lv)。操(cao)作(zuo)頻(pin)率(lv)是指每(mei)小時(shi)(shi)操(cao)作(zuo)的(de)(de)次數;通(tong)電(dian)(dian)(dian)(dian)持續率(lv)是指每(mei)次通(tong)電(dian)(dian)(dian)(dian)時(shi)(shi)間(jian)與(yu)每(mei)次通(tong)電(dian)(dian)(dian)(dian)及不(bu)通(tong)電(dian)(dian)(dian)(dian)時(shi)(shi)間(jian)之和(he)(he)的(de)(de)百分(fen)(fen)比。使(shi)用(yong)(yong)(yong)中(zhong)，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵與(yu)瓦式(shi)(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合(he)(he)時(shi)(shi)用(yong)(yong)(yong)短行(xing)程類(lei);與(yu)皮帶制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合(he)(he)時(shi)(shi)用(yong)(yong)(yong)長(chang)行(xing)程類(lei)。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵通(tong)過液壓方(fang)式(shi)(shi)將電(dian)(dian)(dian)(dian)磁(ci)(ci)力傳遞給制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)構的(de)(de)稱(cheng)液壓制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵。

閥用電磁鐵

供遠距(ju)離操作(zuo)各(ge)種液壓、氣動系統閥(fa)(fa)(fa)(fa)門(men)的(de)電(dian)(dian)磁鐵(tie)。常用(yong)(yong)于各(ge)種金屬切削(xue)機床(chuang)中(zhong)。閥(fa)(fa)(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)不設復位(wei)裝置，而(er)由(you)閥(fa)(fa)(fa)(fa)體(ti)中(zhong)的(de)彈簧使之(zhi)復位(wei)。當(dang)電(dian)(dian)磁鐵(tie)的(de)勵(li)磁繞組通(tong)過電(dian)(dian)流時，電(dian)(dian)磁吸(xi)力即(ji)克(ke)服(fu)彈簧阻(zu)力，使閥(fa)(fa)(fa)(fa)體(ti)的(de)推桿(gan)移(yi)動，將閥(fa)(fa)(fa)(fa)門(men)開啟;當(dang)勵(li)磁繞組斷電(dian)(dian)后，在復位(wei)彈簧作(zuo)用(yong)(yong)下，閥(fa)(fa)(fa)(fa)體(ti)推桿(gan)便推動銜鐵(tie)，使其移(yi)動額定行程處，閥(fa)(fa)(fa)(fa)門(men)關閉(bi)。閥(fa)(fa)(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)分為(wei)濕(shi)式和(he)干式兩種。濕(shi)式閥(fa)(fa)(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)的(de)銜鐵(tie)在液壓油(you)中(zhong)工作(zuo)，由(you)于油(you)的(de)冷卻作(zuo)用(yong)(yong)，使其與具有(you)相同吸(xi)力的(de)電(dian)(dian)磁鐵(tie)相比(bi)，有(you)較小的(de)尺(chi)寸。

電磁鐵的應用

門禁：為什么門禁可(ke)以(yi)(yi)在沒刷卡(ka)時(shi)(shi)把(ba)門牢(lao)(lao)(lao)牢(lao)(lao)(lao)的(de)(de)“抓(zhua)住”？原來單元門是由鋼(gang)材料做成的(de)(de)，那個(ge)金(jin)屬體在通電(dian)時(shi)(shi)可(ke)以(yi)(yi)產生(sheng)強大的(de)(de)磁場(chang)，產生(sheng)的(de)(de)磁力(li)能(neng)把(ba)門牢(lao)(lao)(lao)牢(lao)(lao)(lao)的(de)(de)吸(xi)住，而刷卡(ka)的(de)(de)瞬間，切斷(duan)電(dian)流(liu)，金(jin)屬體失(shi)去磁性，我們就(jiu)可(ke)以(yi)(yi)打開門了。那個(ge)金(jin)屬體其(qi)實是一(yi)塊電(dian)磁鐵。

電(dian)(dian)(dian)磁(ci)起(qi)重(zhong)機(ji)(ji)：最直接的應用之(zhi)一是電(dian)(dian)(dian)磁(ci)起(qi)重(zhong)機(ji)(ji)。電(dian)(dian)(dian)磁(ci)鐵安裝在吊車(che)上，通電(dian)(dian)(dian)后吸起(qi)大量鋼(gang)鐵，移(yi)動到另一個位置(zhi)后切斷電(dian)(dian)(dian)流，鋼(gang)鐵被放下(xia)，免去了打捆的麻煩(fan)。大型電(dian)(dian)(dian)磁(ci)起(qi)重(zhong)機(ji)(ji)一次可以吊起(qi)幾噸鋼(gang)材。

在電(dian)動機、發電(dian)機、電(dian)鈴(ling)和電(dian)磁(ci)繼(ji)電(dian)器(qi)里也(ye)用到電(dian)磁(ci)鐵。全自動洗衣機的進水(shui)、排水(shui)閥門(men)，衛生間(jian)里感應(ying)式沖(chong)水(shui)器(qi)的閥門(men)，也(ye)都是由電(dian)磁(ci)鐵控制(zhi)的。

電(dian)(dian)(dian)磁(ci)鐵的(de)另一(yi)個應用是產(chan)生(sheng)強(qiang)磁(ci)場。現代技術中很多地方需要(yao)的(de)強(qiang)磁(ci)場都由電(dian)(dian)(dian)磁(ci)鐵提供，如大(da)型電(dian)(dian)(dian)動(dong)機、發電(dian)(dian)(dian)機、磁(ci)療設備等。