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。這實際上是廣西電磁鐵原理的(de)最初發現(xian)。1823年，斯(si)特(te)金也做了(le)一(yi)次(ci)類似的(de)實驗：他在(zai)一(yi)根(gen)并(bing)非(fei)是磁(ci)鐵(tie)(tie)(tie)棒(bang)(bang)的(de)U型(xing)(xing)(xing)鐵(tie)(tie)(tie)棒(bang)(bang)上繞(rao)(rao)了(le)18圈銅(tong)裸線，當銅(tong)線與(yu)伏打電(dian)池(chi)接通時，繞(rao)(rao)在(zai)U型(xing)(xing)(xing)鐵(tie)(tie)(tie)棒(bang)(bang)上的(de)銅(tong)線圈即(ji)產生了(le)密(mi)集的(de)磁(ci)場，這樣就使U型(xing)(xing)(xing)鐵(tie)(tie)(tie)棒(bang)(bang)變成了(le)一(yi)塊“電(dian)磁(ci)鐵(tie)(tie)(tie)”。這種電(dian)磁(ci)鐵(tie)(tie)(tie)上的(de)磁(ci)能要比(bi)永磁(ci)能大放多倍，它能吸起比(bi)它重20倍的(de)鐵(tie)(tie)(tie)塊，而當電(dian)源切斷后，U型(xing)(xing)(xing)鐵(tie)(tie)(tie)棒(bang)(bang)就什么(me)鐵(tie)(tie)(tie)塊也吸不住，重新成為一(yi)根(gen)普(pu)通的(de)鐵(tie)(tie)(tie)棒(bang)(bang)。

斯特金(jin)的(de)電(dian)磁鐵發(fa)明，使人們(men)看到了把電(dian)能轉化為磁能的(de)光明前景，這一發(fa)明很快在英國、美國以(yi)及西歐一些沿海國家傳播開來(lai)。

1829年，美國(guo)電(dian)學(xue)家亨(heng)利(li)(li)對斯特金電(dian)磁(ci)(ci)(ci)鐵(tie)裝(zhuang)置(zhi)進行(xing)了(le)一(yi)些革新，絕緣導(dao)線(xian)(xian)代替裸銅(tong)導(dao)線(xian)(xian)，因此不必擔心被(bei)銅(tong)導(dao)線(xian)(xian)過分(fen)靠近而短路。由于導(dao)線(xian)(xian)有了(le)絕緣層，就可以將它們(men)一(yi)圈圈地緊(jin)緊(jin)地繞(rao)在一(yi)起(qi)，由于線(xian)(xian)圈越密集(ji)，產生(sheng)的磁(ci)(ci)(ci)場就越強，這(zhe)樣就大大提高了(le)把電(dian)能(neng)轉(zhuan)化(hua)為磁(ci)(ci)(ci)能(neng)的能(neng)力。到(dao)了(le)1831年，亨(heng)利(li)(li)試制出了(le)一(yi)塊更(geng)新的電(dian)磁(ci)(ci)(ci)鐵(tie)，雖(sui)然它的體積(ji)并(bing)不大，但它能(neng)吸(xi)起(qi)1噸重的鐵(tie)塊。

電磁(ci)(ci)鐵內(nei)部帶有鐵心(xin)的(de)(de)(de)、利用(yong)通有電流的(de)(de)(de)線圈(quan)(quan)使其像(xiang)磁(ci)(ci)鐵一樣具有磁(ci)(ci)性(xing)的(de)(de)(de)裝置叫做電磁(ci)(ci)鐵，通常制(zhi)成條形(xing)或(huo)(huo)蹄形(xing)。鐵心(xin)要用(yong)容(rong)易(yi)磁(ci)(ci)化，又容(rong)易(yi)消失磁(ci)(ci)性(xing)的(de)(de)(de)軟鐵或(huo)(huo)硅鋼(gang)來(lai)制(zhi)做。這樣的(de)(de)(de)電磁(ci)(ci)鐵在通電時有磁(ci)(ci)性(xing)，斷電后就隨(sui)之消失。 電磁(ci)(ci)鐵有許多優點：電磁(ci)(ci)鐵磁(ci)(ci)性(xing)的(de)(de)(de)有無，可以(yi)(yi)用(yong)通、斷電流控制(zhi)。磁(ci)(ci)性(xing)的(de)(de)(de)大小可以(yi)(yi)用(yong)電流的(de)(de)(de)強弱(ruo)或(huo)(huo)線圈(quan)(quan)的(de)(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(fang)潮性能好。

2、經(jing)計算機優(you)化(hua)設計，結(jie)構合理、自重輕(qing)、吸力(li)大(da)、能耗低。

3、勵磁線圈經(jing)特別工(gong)藝處理，提高了線圈的(de)電器和機械性能，絕緣資料熱(re)等級(ji)到達C級(ji)，運(yun)用壽命長。

4、普(pu)通型(xing)電(dian)(dian)磁(ci)鐵的額定通電(dian)(dian)持續率由(you)曩昔的50%提(ti)高到60%，提(ti)高了電(dian)(dian)磁(ci)鐵的運用功(gong)率。

5、超高溫型電磁(ci)鐵采用獨特(te)隔(ge)熱方式，其間被吸物溫度有曩(nang)昔的(de)600℃提高700℃，擴大(da)了(le)電磁(ci)鐵的(de)適用范圍(wei)。

6、裝置、運轉(zhuan)、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)能變換為機械(xie)能以(yi)實現吸合作(zuo)(zuo)功的(de)(de)一(yi)種電(dian)(dian)(dian)器。通常由軟(ruan)磁(ci)(ci)(ci)(ci)材料(liao)制(zhi)成(cheng)的(de)(de)鐵(tie)(tie)(tie)(tie)心(xin)、銜鐵(tie)(tie)(tie)(tie)和勵(li)磁(ci)(ci)(ci)(ci)繞組(zu)(zu)組(zu)(zu)成(cheng)。當勵(li)磁(ci)(ci)(ci)(ci)繞組(zu)(zu)通電(dian)(dian)(dian)時(shi)，繞組(zu)(zu)周圍產生(sheng)磁(ci)(ci)(ci)(ci)場，鐵(tie)(tie)(tie)(tie)心(xin)磁(ci)(ci)(ci)(ci)化，并(bing)產生(sheng)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸力吸引(yin)銜鐵(tie)(tie)(tie)(tie)，使之運動作(zuo)(zuo)功。電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)主要(yao)用于(yu)操(cao)動、牽(qian)引(yin)機械(xie)裝置，以(yi)達到預期的(de)(de)目的(de)(de)。工(gong)(gong)業上常用的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)有制(zhi)動電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)、牽(qian)引(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)、起重電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)和閥用電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等。此外，屬于(yu)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)類的(de)(de)還有用以(yi)傳遞(di)或(huo)隔斷兩軸間的(de)(de)機械(xie)聯(lian)系的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)聯(lian)軸器;用在機床工(gong)(gong)作(zuo)(zuo)臺(tai)上以(yi)吸牢磁(ci)(ci)(ci)(ci)性材料(liao)工(gong)(gong)件的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸盤;供高(gao)能物理、核(he)聚變研(yan)究、磁(ci)(ci)(ci)(ci)流體發電(dian)(dian)(dian)和高(gao)速懸浮列車(che)等方面使用的(de)(de)、能產生(sheng)高(gao)達數十特（斯拉）的(de)(de)磁(ci)(ci)(ci)(ci)通密度而幾乎不(bu)消耗繞組(zu)(zu)功率的(de)(de)超導電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)等。

起重電磁鐵

用來吊(diao)運和(he)裝卸鐵(tie)磁(ci)(ci)(ci)性物體的電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。工(gong)業(ye)上常(chang)用以吊(diao)運或(huo)裝卸鐵(tie)礦石、鐵(tie)砂、廢鋼(gang)(gang)鐵(tie)、鋼(gang)(gang)錠、鋼(gang)(gang)軌以及各種鋼(gang)(gang)材和(he)鋼(gang)(gang)質工(gong)件。起重(zhong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)常(chang)做成圓盤形或(huo)矩形，并(bing)帶有內磁(ci)(ci)(ci)極(ji)和(he)外磁(ci)(ci)(ci)極(ji)。當勵磁(ci)(ci)(ci)繞(rao)組通(tong)電(dian)(dian)后，內外磁(ci)(ci)(ci)極(ji)均被(bei)磁(ci)(ci)(ci)化，吸引鋼(gang)(gang)質材料或(huo)工(gong)件（相(xiang)當于(yu)一般電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)中的銜鐵(tie)），形成一個(ge)閉合(he)的磁(ci)(ci)(ci)路(lu)。為保護(hu)勵磁(ci)(ci)(ci)繞(rao)組，使之不因磁(ci)(ci)(ci)極(ji)與(yu)被(bei)吸引物體間的機械撞擊所(suo)損傷，起重(zhong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)常(chang)采用甲殼式結構，并(bing)且采用直流勵磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)(qian)引(yin)(yin)和推斥機(ji)械(xie)裝置(zhi)用(yong)的(de)一(yi)種(zhong)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)。主(zhu)要(yao)用(yong)于各種(zhong)自動設備(bei)(bei)中，以實(shi)現遠(yuan)距離控制(zhi)。為了能夠在長行(xing)程下(xia)獲得(de)較大的(de)電(dian)(dian)(dian)磁(ci)(ci)吸(xi)(xi)力，牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)一(yi)般采用(yong)吸(xi)(xi)引(yin)(yin)特性(xing)比較平坦的(de)甲殼式結構(gou)(gou)。其內部裝有鐵(tie)(tie)(tie)(tie)(tie)心(xin)、銜(xian)鐵(tie)(tie)(tie)(tie)(tie)和勵磁(ci)(ci)線圈(quan)。使(shi)用(yong)時，將鐵(tie)(tie)(tie)(tie)(tie)心(xin)固定(ding)在機(ji)械(xie)裝置(zhi)的(de)靜止部件(jian)上(shang)，銜(xian)鐵(tie)(tie)(tie)(tie)(tie)則連接在牽(qian)(qian)引(yin)(yin)桿上(shang)。當(dang)勵磁(ci)(ci)繞(rao)組(zu)通(tong)電(dian)(dian)(dian)后，鐵(tie)(tie)(tie)(tie)(tie)心(xin)被磁(ci)(ci)化(hua)，產生電(dian)(dian)(dian)磁(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)(yin)銜(xian)鐵(tie)(tie)(tie)(tie)(tie)，后者(zhe)則通(tong)過牽(qian)(qian)引(yin)(yin)桿來操縱(zong)所控制(zhi)的(de)機(ji)械(xie)裝置(zhi)的(de)機(ji)構(gou)(gou)。為了適應不同控制(zhi)對象的(de)需要(yao)，牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)有拉動式和推動式兩種(zhong)，但都不具備(bei)(bei)復位裝置(zhi)。牽(qian)(qian)引(yin)(yin)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)的(de)主(zhu)要(yao)技術指標為一(yi)定(ding)行(xing)程下(xia)的(de)電(dian)(dian)(dian)磁(ci)(ci)吸(xi)(xi)力、操作(zuo)頻率和壽命。

制動電磁鐵

作(zuo)機械制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)用(yong)(yong)的(de)一種電(dian)(dian)磁(ci)(ci)鐵。主要用(yong)(yong)于電(dian)(dian)力驅動(dong)(dong)(dong)裝置和起(qi)重(zhong)運輸設備中(zhong)，并與(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器配(pei)合(he)使(shi)用(yong)(yong)，使(shi)電(dian)(dian)動(dong)(dong)(dong)機準(zhun)確停(ting)車(che)和懸吊著的(de)重(zhong)物不致墜落(luo)。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵按銜鐵行程(cheng)(cheng)分(fen)為長行程(cheng)(cheng)和短行程(cheng)(cheng)兩類;按勵磁(ci)(ci)方式(shi)分(fen)為直流(liu)和交流(liu)、并勵和串(chuan)勵以及(ji)(ji)單相(xiang)和三相(xiang)等種類。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵的(de)工作(zuo)原(yuan)理是(shi)：當電(dian)(dian)磁(ci)(ci)鐵的(de)繞組通(tong)(tong)電(dian)(dian)后(hou)，銜鐵被吸向鐵心(xin)，并通(tong)(tong)過制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器中(zhong)的(de)停(ting)檔壓迫制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿(gan)，使(shi)之(zhi)移動(dong)(dong)(dong)，從而迫使(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器松閘。切斷線圈(quan)電(dian)(dian)源(yuan)后(hou)，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)桿(gan)在彈(dan)簧作(zuo)用(yong)(yong)下使(shi)銜鐵脫離磁(ci)(ci)軛，而制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器則將機構剎(cha)住。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵的(de)主要技術參(can)數是(shi)行程(cheng)(cheng)、一定(ding)行程(cheng)(cheng)下的(de)電(dian)(dian)磁(ci)(ci)吸力、操作(zuo)頻(pin)率和通(tong)(tong)電(dian)(dian)持續率。操作(zuo)頻(pin)率是(shi)指每小時(shi)(shi)操作(zuo)的(de)次數;通(tong)(tong)電(dian)(dian)持續率是(shi)指每次通(tong)(tong)電(dian)(dian)時(shi)(shi)間與(yu)每次通(tong)(tong)電(dian)(dian)及(ji)(ji)不通(tong)(tong)電(dian)(dian)時(shi)(shi)間之(zhi)和的(de)百(bai)分(fen)比。使(shi)用(yong)(yong)中(zhong)，制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵與(yu)瓦式(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配(pei)合(he)時(shi)(shi)用(yong)(yong)短行程(cheng)(cheng)類;與(yu)皮帶制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配(pei)合(he)時(shi)(shi)用(yong)(yong)長行程(cheng)(cheng)類。制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵通(tong)(tong)過液壓方式(shi)將電(dian)(dian)磁(ci)(ci)力傳遞給(gei)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)機構的(de)稱液壓制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁(ci)(ci)鐵。

閥用電磁鐵

供(gong)遠距離操(cao)作各種(zhong)液壓、氣(qi)動(dong)系統(tong)閥(fa)門(men)(men)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用于各種(zhong)金(jin)屬(shu)切(qie)削機(ji)床(chuang)中。閥(fa)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設復(fu)(fu)(fu)位裝置，而由閥(fa)體中的(de)(de)(de)(de)彈簧(huang)使之復(fu)(fu)(fu)位。當電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)(de)勵磁(ci)(ci)(ci)繞組通過電(dian)(dian)(dian)(dian)流(liu)時，電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力(li)(li)即(ji)克服彈簧(huang)阻力(li)(li)，使閥(fa)體的(de)(de)(de)(de)推桿移(yi)動(dong)，將閥(fa)門(men)(men)開啟;當勵磁(ci)(ci)(ci)繞組斷電(dian)(dian)(dian)(dian)后，在復(fu)(fu)(fu)位彈簧(huang)作用下，閥(fa)體推桿便推動(dong)銜(xian)鐵(tie)(tie)，使其移(yi)動(dong)額定行程(cheng)處(chu)，閥(fa)門(men)(men)關閉。閥(fa)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分為濕式(shi)和干式(shi)兩種(zhong)。濕式(shi)閥(fa)用電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)(de)銜(xian)鐵(tie)(tie)在液壓油中工作，由于油的(de)(de)(de)(de)冷卻作用，使其與具有相(xiang)同吸(xi)力(li)(li)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相(xiang)比，有較小的(de)(de)(de)(de)尺寸。

電磁鐵的應用

門(men)(men)禁：為什(shen)么門(men)(men)禁可(ke)(ke)以在沒刷(shua)卡時把(ba)門(men)(men)牢(lao)(lao)(lao)牢(lao)(lao)(lao)的(de)“抓住”？原(yuan)來單元門(men)(men)是由鋼材料做成的(de)，那個金(jin)屬(shu)體在通(tong)電時可(ke)(ke)以產(chan)生強大的(de)磁場，產(chan)生的(de)磁力能把(ba)門(men)(men)牢(lao)(lao)(lao)牢(lao)(lao)(lao)的(de)吸住，而刷(shua)卡的(de)瞬間，切斷電流，金(jin)屬(shu)體失去磁性，我(wo)們就可(ke)(ke)以打(da)開門(men)(men)了。那個金(jin)屬(shu)體其(qi)實是一塊電磁鐵。

電磁(ci)起(qi)(qi)重(zhong)機(ji)(ji)：最(zui)直接(jie)的應用之一(yi)是(shi)電磁(ci)起(qi)(qi)重(zhong)機(ji)(ji)。電磁(ci)鐵安(an)裝在吊(diao)車上，通電后吸起(qi)(qi)大量鋼鐵，移動(dong)到另一(yi)個位置后切(qie)斷(duan)電流，鋼鐵被放(fang)下，免去(qu)了(le)打(da)捆(kun)的麻煩。大型電磁(ci)起(qi)(qi)重(zhong)機(ji)(ji)一(yi)次可以吊(diao)起(qi)(qi)幾噸鋼材。

在電(dian)(dian)動機(ji)、發電(dian)(dian)機(ji)、電(dian)(dian)鈴(ling)和(he)電(dian)(dian)磁(ci)(ci)繼電(dian)(dian)器里(li)也(ye)(ye)用到電(dian)(dian)磁(ci)(ci)鐵。全(quan)自動洗衣機(ji)的(de)進水、排水閥(fa)門(men)，衛(wei)生間里(li)感應式(shi)沖水器的(de)閥(fa)門(men)，也(ye)(ye)都(dou)是由電(dian)(dian)磁(ci)(ci)鐵控制的(de)。

電(dian)(dian)磁鐵(tie)的另一個應用是產生強(qiang)磁場(chang)。現代技(ji)術中很多(duo)地(di)方需要的強(qiang)磁場(chang)都由電(dian)(dian)磁鐵(tie)提供，如大型電(dian)(dian)動機、發電(dian)(dian)機、磁療設(she)備等。