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。這實際上是梅州電磁鐵原理的(de)最初發現。1823年，斯特金(jin)也(ye)做了一次類似的(de)實驗：他在一根并(bing)非是磁(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)的(de)U型(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)上繞了18圈(quan)銅(tong)(tong)(tong)裸線，當(dang)銅(tong)(tong)(tong)線與伏(fu)打電池接通(tong)時，繞在U型(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)上的(de)銅(tong)(tong)(tong)線圈(quan)即(ji)產生了密集的(de)磁(ci)場，這(zhe)樣(yang)就使U型(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)變(bian)成(cheng)了一塊“電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)”。這(zhe)種電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)上的(de)磁(ci)能要比永磁(ci)能大放(fang)多倍，它能吸(xi)起比它重(zhong)20倍的(de)鐵(tie)(tie)(tie)(tie)(tie)(tie)塊，而當(dang)電源切斷(duan)后，U型(xing)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)就什(shen)么(me)鐵(tie)(tie)(tie)(tie)(tie)(tie)塊也(ye)吸(xi)不住，重(zhong)新成(cheng)為(wei)一根普通(tong)的(de)鐵(tie)(tie)(tie)(tie)(tie)(tie)棒(bang)(bang)。

斯特金的(de)電(dian)磁鐵發(fa)明，使人們看(kan)到了把電(dian)能(neng)轉化為(wei)磁能(neng)的(de)光明前(qian)景，這一(yi)發(fa)明很快在英國、美國以(yi)及西歐一(yi)些沿海國家傳播開來。

1829年，美(mei)國(guo)電學家(jia)亨(heng)利對斯(si)特金電磁鐵裝置進行了一(yi)(yi)些革新，絕緣導(dao)線(xian)代替裸銅(tong)導(dao)線(xian)，因此不(bu)必擔心被銅(tong)導(dao)線(xian)過(guo)分靠近而(er)短路。由(you)于(yu)導(dao)線(xian)有了絕緣層，就可以(yi)將它們一(yi)(yi)圈圈地緊緊地繞(rao)在(zai)一(yi)(yi)起，由(you)于(yu)線(xian)圈越(yue)密集，產生的(de)磁場就越(yue)強(qiang)，這(zhe)樣就大大提(ti)高了把電能轉(zhuan)化為(wei)磁能的(de)能力。到了1831年，亨(heng)利試制出(chu)了一(yi)(yi)塊更新的(de)電磁鐵，雖然它的(de)體積并不(bu)大，但它能吸起1噸重(zhong)的(de)鐵塊。

電磁(ci)鐵(tie)(tie)(tie)內(nei)部帶有鐵(tie)(tie)(tie)心的(de)(de)、利用(yong)通(tong)(tong)有電流的(de)(de)線圈使(shi)其(qi)像磁(ci)鐵(tie)(tie)(tie)一樣具有磁(ci)性(xing)(xing)(xing)的(de)(de)裝置叫(jiao)做(zuo)(zuo)電磁(ci)鐵(tie)(tie)(tie)，通(tong)(tong)常(chang)制(zhi)成條(tiao)形或蹄形。鐵(tie)(tie)(tie)心要(yao)用(yong)容易磁(ci)化(hua)，又容易消失磁(ci)性(xing)(xing)(xing)的(de)(de)軟(ruan)鐵(tie)(tie)(tie)或硅鋼(gang)來(lai)制(zhi)做(zuo)(zuo)。這樣的(de)(de)電磁(ci)鐵(tie)(tie)(tie)在(zai)通(tong)(tong)電時有磁(ci)性(xing)(xing)(xing)，斷電后(hou)就隨之消失。 電磁(ci)鐵(tie)(tie)(tie)有許多優點：電磁(ci)鐵(tie)(tie)(tie)磁(ci)性(xing)(xing)(xing)的(de)(de)有無，可以用(yong)通(tong)(tong)、斷電流控制(zhi)。磁(ci)性(xing)(xing)(xing)的(de)(de)大小可以用(yong)電流的(de)(de)強弱或線圈的(de)(de)匝數來(lai)控制(zhi)。

電磁鐵的主要特點

1、采用全密封(feng)結構，防潮(chao)性能好。

2、經計算機優化設計，結構合理(li)、自(zi)重(zhong)輕、吸力大、能耗(hao)低。

3、勵磁線圈(quan)經特別工藝(yi)處理，提高(gao)了線圈(quan)的(de)電器和機械(xie)性能，絕緣資料熱等級到達(da)C級，運用壽命長。

4、普(pu)通型電(dian)磁(ci)鐵(tie)的額(e)定通電(dian)持續(xu)率由曩昔的50%提高(gao)到(dao)60%，提高(gao)了電(dian)磁(ci)鐵(tie)的運(yun)用(yong)功率。

5、超高(gao)溫型電(dian)磁(ci)鐵(tie)(tie)采用(yong)(yong)獨特隔熱方(fang)式，其間被吸物溫度有曩昔的600℃提高(gao)700℃，擴大了電(dian)磁(ci)鐵(tie)(tie)的適用(yong)(yong)范(fan)圍。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)磁(ci)(ci)(ci)能變換為機械(xie)能以(yi)(yi)實現(xian)吸合作(zuo)功的(de)(de)(de)一種電(dian)(dian)器(qi)。通常由軟磁(ci)(ci)(ci)材料制(zhi)成(cheng)的(de)(de)(de)鐵(tie)(tie)(tie)(tie)心(xin)、銜(xian)鐵(tie)(tie)(tie)(tie)和(he)勵(li)(li)磁(ci)(ci)(ci)繞組(zu)組(zu)成(cheng)。當勵(li)(li)磁(ci)(ci)(ci)繞組(zu)通電(dian)(dian)時，繞組(zu)周圍產生(sheng)(sheng)磁(ci)(ci)(ci)場，鐵(tie)(tie)(tie)(tie)心(xin)磁(ci)(ci)(ci)化，并產生(sheng)(sheng)電(dian)(dian)磁(ci)(ci)(ci)吸力吸引(yin)銜(xian)鐵(tie)(tie)(tie)(tie)，使之運動(dong)作(zuo)功。電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)主要用(yong)于(yu)操動(dong)、牽引(yin)機械(xie)裝置，以(yi)(yi)達(da)到預期的(de)(de)(de)目的(de)(de)(de)。工(gong)業上常用(yong)的(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)有(you)制(zhi)動(dong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)、牽引(yin)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)閥用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等(deng)。此(ci)外(wai)，屬于(yu)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)類(lei)的(de)(de)(de)還有(you)用(yong)以(yi)(yi)傳遞或隔斷兩軸(zhou)間的(de)(de)(de)機械(xie)聯(lian)系(xi)的(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)聯(lian)軸(zhou)器(qi);用(yong)在(zai)機床工(gong)作(zuo)臺上以(yi)(yi)吸牢磁(ci)(ci)(ci)性材料工(gong)件的(de)(de)(de)電(dian)(dian)磁(ci)(ci)(ci)吸盤;供高(gao)能物理、核聚變研究、磁(ci)(ci)(ci)流體發電(dian)(dian)和(he)高(gao)速懸浮列車等(deng)方面使用(yong)的(de)(de)(de)、能產生(sheng)(sheng)高(gao)達(da)數十特（斯拉）的(de)(de)(de)磁(ci)(ci)(ci)通密度而(er)幾乎不(bu)消耗(hao)繞組(zu)功率的(de)(de)(de)超導電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等(deng)。

起重電磁鐵

用來吊運和裝卸(xie)(xie)鐵(tie)(tie)磁(ci)(ci)(ci)性物(wu)體的(de)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。工業(ye)上常用以吊運或裝卸(xie)(xie)鐵(tie)(tie)礦石(shi)、鐵(tie)(tie)砂、廢鋼鐵(tie)(tie)、鋼錠、鋼軌以及各種鋼材和鋼質工件。起(qi)重(zhong)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)通(tong)常做(zuo)成圓(yuan)盤形或矩形，并(bing)帶有內(nei)磁(ci)(ci)(ci)極和外(wai)磁(ci)(ci)(ci)極。當(dang)勵磁(ci)(ci)(ci)繞組通(tong)電(dian)后，內(nei)外(wai)磁(ci)(ci)(ci)極均(jun)被磁(ci)(ci)(ci)化，吸引鋼質材料或工件（相當(dang)于一般(ban)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)中的(de)銜鐵(tie)(tie)），形成一個閉合(he)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)極與被吸引物(wu)體間的(de)機械撞擊(ji)所(suo)損傷，起(qi)重(zhong)電(dian)磁(ci)(ci)(ci)鐵(tie)(tie)通(tong)常采(cai)用甲殼式結構，并(bing)且采(cai)用直流(liu)勵磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)(qian)引(yin)(yin)(yin)(yin)和(he)(he)推(tui)斥(chi)機械裝置(zhi)(zhi)用的(de)(de)(de)一(yi)(yi)種(zhong)電(dian)(dian)磁(ci)鐵(tie)(tie)。主要(yao)用于各種(zhong)自動設備中(zhong)，以實現遠距離控制。為(wei)了(le)(le)能夠在(zai)長行(xing)程下獲得(de)較大的(de)(de)(de)電(dian)(dian)磁(ci)吸(xi)力，牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)一(yi)(yi)般采用吸(xi)引(yin)(yin)(yin)(yin)特性比較平坦的(de)(de)(de)甲(jia)殼式結構。其(qi)內部(bu)裝有鐵(tie)(tie)心(xin)、銜(xian)(xian)鐵(tie)(tie)和(he)(he)勵磁(ci)線圈(quan)。使用時(shi)，將鐵(tie)(tie)心(xin)固定(ding)在(zai)機械裝置(zhi)(zhi)的(de)(de)(de)靜止部(bu)件上(shang)，銜(xian)(xian)鐵(tie)(tie)則連(lian)接在(zai)牽(qian)(qian)引(yin)(yin)(yin)(yin)桿上(shang)。當勵磁(ci)繞組(zu)通電(dian)(dian)后，鐵(tie)(tie)心(xin)被磁(ci)化，產生電(dian)(dian)磁(ci)吸(xi)力吸(xi)引(yin)(yin)(yin)(yin)銜(xian)(xian)鐵(tie)(tie)，后者則通過牽(qian)(qian)引(yin)(yin)(yin)(yin)桿來操(cao)縱所控制的(de)(de)(de)機械裝置(zhi)(zhi)的(de)(de)(de)機構。為(wei)了(le)(le)適應(ying)不同控制對(dui)象的(de)(de)(de)需要(yao)，牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)有拉動式和(he)(he)推(tui)動式兩種(zhong)，但都(dou)不具(ju)備復位(wei)裝置(zhi)(zhi)。牽(qian)(qian)引(yin)(yin)(yin)(yin)電(dian)(dian)磁(ci)鐵(tie)(tie)的(de)(de)(de)主要(yao)技術指(zhi)標(biao)為(wei)一(yi)(yi)定(ding)行(xing)程下的(de)(de)(de)電(dian)(dian)磁(ci)吸(xi)力、操(cao)作頻(pin)率和(he)(he)壽命。

制動電磁鐵

作(zuo)(zuo)(zuo)機械制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)用的一(yi)(yi)種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)。主要用于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)起重(zhong)運輸設備中(zhong)(zhong)，并與(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)配合使(shi)(shi)(shi)用，使(shi)(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機準(zhun)確停車和(he)(he)懸吊(diao)著的重(zhong)物不(bu)致墜落。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)按銜鐵(tie)行程(cheng)(cheng)分(fen)為長(chang)行程(cheng)(cheng)和(he)(he)短行程(cheng)(cheng)兩類;按勵磁(ci)(ci)方式分(fen)為直流和(he)(he)交流、并勵和(he)(he)串勵以(yi)及(ji)(ji)單相(xiang)(xiang)和(he)(he)三相(xiang)(xiang)等種(zhong)類。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的工作(zuo)(zuo)(zuo)原理是：當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的繞組(zu)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)后，銜鐵(tie)被吸(xi)(xi)向鐵(tie)心，并通(tong)過(guo)(guo)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)中(zhong)(zhong)的停檔壓(ya)(ya)迫(po)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)，使(shi)(shi)(shi)之移(yi)動(dong)(dong)(dong)(dong)(dong)，從而迫(po)使(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)松閘(zha)。切斷線圈電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)在彈簧作(zuo)(zuo)(zuo)用下使(shi)(shi)(shi)銜鐵(tie)脫離磁(ci)(ci)軛，而制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)則(ze)將(jiang)機構剎住。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)的主要技術參數是行程(cheng)(cheng)、一(yi)(yi)定行程(cheng)(cheng)下的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)吸(xi)(xi)力、操作(zuo)(zuo)(zuo)頻率(lv)(lv)和(he)(he)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率(lv)(lv)。操作(zuo)(zuo)(zuo)頻率(lv)(lv)是指(zhi)每(mei)(mei)小(xiao)時操作(zuo)(zuo)(zuo)的次(ci)(ci)數;通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率(lv)(lv)是指(zhi)每(mei)(mei)次(ci)(ci)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間與(yu)每(mei)(mei)次(ci)(ci)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)(ji)不(bu)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間之和(he)(he)的百分(fen)比。使(shi)(shi)(shi)用中(zhong)(zhong)，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)與(yu)瓦(wa)式制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)相(xiang)(xiang)配合時用短行程(cheng)(cheng)類;與(yu)皮帶制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)(qi)相(xiang)(xiang)配合時用長(chang)行程(cheng)(cheng)類。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)通(tong)過(guo)(guo)液壓(ya)(ya)方式將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)力傳遞給制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)機構的稱液壓(ya)(ya)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)。

閥用電磁鐵

供(gong)遠距離操作(zuo)各種液(ye)壓、氣動(dong)系統閥(fa)(fa)門的電(dian)(dian)磁鐵(tie)(tie)(tie)。常用(yong)(yong)于(yu)各種金屬切(qie)削機床(chuang)中(zhong)。閥(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)(tie)(tie)不設(she)復(fu)位(wei)裝置，而由閥(fa)(fa)體(ti)中(zhong)的彈簧使之(zhi)復(fu)位(wei)。當電(dian)(dian)磁鐵(tie)(tie)(tie)的勵(li)磁繞組通過(guo)電(dian)(dian)流(liu)時，電(dian)(dian)磁吸力(li)(li)即克服彈簧阻力(li)(li)，使閥(fa)(fa)體(ti)的推(tui)桿(gan)移動(dong)，將(jiang)閥(fa)(fa)門開啟;當勵(li)磁繞組斷(duan)電(dian)(dian)后(hou)，在復(fu)位(wei)彈簧作(zuo)用(yong)(yong)下，閥(fa)(fa)體(ti)推(tui)桿(gan)便推(tui)動(dong)銜(xian)鐵(tie)(tie)(tie)，使其移動(dong)額定行程處，閥(fa)(fa)門關(guan)閉。閥(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)(tie)(tie)分為濕式(shi)和干式(shi)兩種。濕式(shi)閥(fa)(fa)用(yong)(yong)電(dian)(dian)磁鐵(tie)(tie)(tie)的銜(xian)鐵(tie)(tie)(tie)在液(ye)壓油(you)中(zhong)工作(zuo)，由于(yu)油(you)的冷卻作(zuo)用(yong)(yong)，使其與具有相同吸力(li)(li)的電(dian)(dian)磁鐵(tie)(tie)(tie)相比(bi)，有較小的尺寸(cun)。

電磁鐵的應用

門(men)禁(jin)：為什么門(men)禁(jin)可(ke)以(yi)在(zai)沒刷卡(ka)時把(ba)門(men)牢牢的(de)(de)(de)“抓(zhua)住”？原來單(dan)元門(men)是由鋼材料做成的(de)(de)(de)，那(nei)(nei)個金屬體在(zai)通(tong)電時可(ke)以(yi)產(chan)(chan)生強大的(de)(de)(de)磁(ci)場，產(chan)(chan)生的(de)(de)(de)磁(ci)力能(neng)把(ba)門(men)牢牢的(de)(de)(de)吸住，而刷卡(ka)的(de)(de)(de)瞬間，切斷電流，金屬體失去磁(ci)性，我們就可(ke)以(yi)打開門(men)了(le)。那(nei)(nei)個金屬體其實是一塊電磁(ci)鐵。

電(dian)磁起(qi)重機：最直接的(de)應用(yong)之(zhi)一是電(dian)磁起(qi)重機。電(dian)磁鐵安(an)裝(zhuang)在(zai)吊車(che)上，通電(dian)后吸起(qi)大量鋼(gang)鐵，移動(dong)到(dao)另一個位(wei)置后切斷電(dian)流，鋼(gang)鐵被放下(xia)，免去了(le)打捆(kun)的(de)麻煩。大型電(dian)磁起(qi)重機一次(ci)可以吊起(qi)幾(ji)噸鋼(gang)材。

在電(dian)動機、發(fa)電(dian)機、電(dian)鈴和(he)電(dian)磁繼電(dian)器(qi)里也用到電(dian)磁鐵。全自(zi)動洗衣機的(de)進水、排水閥(fa)(fa)門(men)，衛(wei)生(sheng)間里感應(ying)式沖水器(qi)的(de)閥(fa)(fa)門(men)，也都是由電(dian)磁鐵控制的(de)。

電(dian)磁鐵的(de)另(ling)一個(ge)應(ying)用(yong)是產生強磁場。現代技術中(zhong)很多地方需要的(de)強磁場都由(you)電(dian)磁鐵提供(gong)，如大型(xing)電(dian)動機、發電(dian)機、磁療設備等。