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。這實際上是天津電磁鐵原(yuan)理的(de)(de)最初發現(xian)。1823年，斯特(te)金也做了(le)一(yi)次類似的(de)(de)實驗：他在(zai)一(yi)根并非是磁鐵(tie)(tie)(tie)棒(bang)(bang)(bang)的(de)(de)U型鐵(tie)(tie)(tie)棒(bang)(bang)(bang)上(shang)繞了(le)18圈(quan)銅裸線，當(dang)銅線與伏打電(dian)池接通(tong)時，繞在(zai)U型鐵(tie)(tie)(tie)棒(bang)(bang)(bang)上(shang)的(de)(de)銅線圈(quan)即產生(sheng)了(le)密集的(de)(de)磁場(chang)，這(zhe)樣就(jiu)使U型鐵(tie)(tie)(tie)棒(bang)(bang)(bang)變成了(le)一(yi)塊“電(dian)磁鐵(tie)(tie)(tie)”。這(zhe)種電(dian)磁鐵(tie)(tie)(tie)上(shang)的(de)(de)磁能要比永磁能大放(fang)多(duo)倍，它能吸(xi)起(qi)比它重(zhong)20倍的(de)(de)鐵(tie)(tie)(tie)塊，而當(dang)電(dian)源切斷后，U型鐵(tie)(tie)(tie)棒(bang)(bang)(bang)就(jiu)什么(me)鐵(tie)(tie)(tie)塊也吸(xi)不住，重(zhong)新成為一(yi)根普通(tong)的(de)(de)鐵(tie)(tie)(tie)棒(bang)(bang)(bang)。

斯特金的(de)電磁鐵(tie)發(fa)明(ming)，使(shi)人們看到了把電能轉化(hua)為(wei)磁能的(de)光明(ming)前(qian)景，這(zhe)一(yi)發(fa)明(ming)很快在英國(guo)、美國(guo)以(yi)及西(xi)歐一(yi)些沿海國(guo)家(jia)傳播開來。

1829年(nian)，美國電(dian)(dian)學(xue)家亨(heng)利(li)對斯(si)特金電(dian)(dian)磁(ci)鐵(tie)(tie)裝置進行(xing)了一些革新(xin)，絕(jue)緣導(dao)線(xian)代替裸銅(tong)導(dao)線(xian)，因此不必擔心被銅(tong)導(dao)線(xian)過分靠(kao)近而短路。由(you)于導(dao)線(xian)有(you)了絕(jue)緣層，就可以(yi)將它們(men)一圈(quan)圈(quan)地緊緊地繞在一起(qi)，由(you)于線(xian)圈(quan)越(yue)密集，產(chan)生的(de)磁(ci)場(chang)就越(yue)強，這樣就大(da)大(da)提高了把電(dian)(dian)能(neng)(neng)轉化為磁(ci)能(neng)(neng)的(de)能(neng)(neng)力。到了1831年(nian)，亨(heng)利(li)試制出了一塊更新(xin)的(de)電(dian)(dian)磁(ci)鐵(tie)(tie)，雖然(ran)它的(de)體積(ji)并不大(da)，但它能(neng)(neng)吸起(qi)1噸重的(de)鐵(tie)(tie)塊。

電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)內(nei)部帶有(you)鐵(tie)(tie)心(xin)的、利用(yong)通(tong)有(you)電(dian)流(liu)的線(xian)圈使其像磁(ci)(ci)(ci)(ci)鐵(tie)(tie)一樣(yang)具有(you)磁(ci)(ci)(ci)(ci)性(xing)的裝置(zhi)叫做電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)，通(tong)常制(zhi)成條(tiao)形或蹄形。鐵(tie)(tie)心(xin)要用(yong)容易磁(ci)(ci)(ci)(ci)化，又(you)容易消失(shi)磁(ci)(ci)(ci)(ci)性(xing)的軟鐵(tie)(tie)或硅鋼來制(zhi)做。這樣(yang)的電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)在通(tong)電(dian)時有(you)磁(ci)(ci)(ci)(ci)性(xing)，斷電(dian)后就隨之消失(shi)。 電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有(you)許多優點：電(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)磁(ci)(ci)(ci)(ci)性(xing)的有(you)無，可以(yi)用(yong)通(tong)、斷電(dian)流(liu)控制(zhi)。磁(ci)(ci)(ci)(ci)性(xing)的大小可以(yi)用(yong)電(dian)流(liu)的強弱或線(xian)圈的匝數(shu)來控制(zhi)。

電磁鐵的主要特點

1、采(cai)用(yong)全密封結構，防(fang)潮性能好。

2、經計算機(ji)優化(hua)設計，結(jie)構合理(li)、自重(zhong)輕、吸力大(da)、能(neng)耗低(di)。

3、勵磁線圈經(jing)特別工藝(yi)處理，提高了(le)線圈的電器和(he)機械性能(neng)，絕緣資料(liao)熱(re)等級(ji)到達C級(ji)，運用壽命長。

4、普通型電磁鐵的(de)(de)額(e)定通電持續(xu)率(lv)由(you)曩(nang)昔的(de)(de)50%提高(gao)到60%，提高(gao)了電磁鐵的(de)(de)運用功(gong)率(lv)。

5、超高溫(wen)型電磁鐵采(cai)用獨(du)特(te)隔熱方式，其間被吸(xi)物(wu)溫(wen)度有曩昔的(de)(de)600℃提高700℃，擴(kuo)大了電磁鐵的(de)(de)適用范圍。

6、裝置、運(yun)轉、保護(hu)簡潔。

電磁鐵工作原理

將電(dian)(dian)磁(ci)(ci)(ci)能(neng)變(bian)換為機(ji)械(xie)(xie)能(neng)以(yi)實現吸(xi)合作(zuo)功(gong)的(de)(de)一種電(dian)(dian)器。通常由(you)軟磁(ci)(ci)(ci)材料(liao)制成的(de)(de)鐵(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)和(he)勵磁(ci)(ci)(ci)繞組組成。當勵磁(ci)(ci)(ci)繞組通電(dian)(dian)時，繞組周圍產生(sheng)磁(ci)(ci)(ci)場，鐵(tie)(tie)(tie)心磁(ci)(ci)(ci)化，并產生(sheng)電(dian)(dian)磁(ci)(ci)(ci)吸(xi)力吸(xi)引銜(xian)鐵(tie)(tie)(tie)，使之運動作(zuo)功(gong)。電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)主要用(yong)于(yu)操動、牽引機(ji)械(xie)(xie)裝置(zhi)，以(yi)達(da)到預期的(de)(de)目的(de)(de)。工業上常用(yong)的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)有(you)制動電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)、牽引電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)、起(qi)重電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)和(he)閥用(yong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。此(ci)外，屬于(yu)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)類的(de)(de)還有(you)用(yong)以(yi)傳遞或(huo)隔斷兩軸(zhou)間的(de)(de)機(ji)械(xie)(xie)聯系的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)聯軸(zhou)器;用(yong)在機(ji)床(chuang)工作(zuo)臺上以(yi)吸(xi)牢磁(ci)(ci)(ci)性材料(liao)工件的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)吸(xi)盤;供(gong)高(gao)能(neng)物理、核(he)聚變(bian)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)、能(neng)產生(sheng)高(gao)達(da)數十特（斯拉）的(de)(de)磁(ci)(ci)(ci)通密度而幾乎不消耗繞組功(gong)率的(de)(de)超(chao)導(dao)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。

起重電磁鐵

用(yong)(yong)(yong)來吊運和裝(zhuang)卸鐵(tie)(tie)(tie)磁(ci)(ci)(ci)(ci)性物體的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)。工業上常(chang)(chang)用(yong)(yong)(yong)以吊運或裝(zhuang)卸鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂(sha)、廢鋼(gang)鐵(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌以及各種(zhong)鋼(gang)材(cai)和鋼(gang)質工件。起(qi)重(zhong)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)通常(chang)(chang)做成圓(yuan)盤形(xing)(xing)或矩形(xing)(xing)，并帶有內(nei)磁(ci)(ci)(ci)(ci)極(ji)和外(wai)磁(ci)(ci)(ci)(ci)極(ji)。當勵(li)磁(ci)(ci)(ci)(ci)繞組通電(dian)(dian)后(hou)，內(nei)外(wai)磁(ci)(ci)(ci)(ci)極(ji)均被磁(ci)(ci)(ci)(ci)化，吸引鋼(gang)質材(cai)料(liao)或工件（相當于一般電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)中的(de)銜鐵(tie)(tie)(tie)），形(xing)(xing)成一個(ge)閉合的(de)磁(ci)(ci)(ci)(ci)路。為保護(hu)勵(li)磁(ci)(ci)(ci)(ci)繞組，使之不因(yin)磁(ci)(ci)(ci)(ci)極(ji)與被吸引物體間的(de)機械撞擊所損傷(shang)，起(qi)重(zhong)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)通常(chang)(chang)采(cai)用(yong)(yong)(yong)甲殼式結構，并且采(cai)用(yong)(yong)(yong)直流勵(li)磁(ci)(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)和(he)(he)推斥機(ji)械裝(zhuang)置(zhi)(zhi)用(yong)的(de)(de)一(yi)種(zhong)電磁(ci)(ci)鐵(tie)。主要(yao)(yao)用(yong)于各種(zhong)自動設(she)備中，以實現遠距離控(kong)制(zhi)。為了能夠在長(chang)行(xing)程下(xia)獲得較大的(de)(de)電磁(ci)(ci)吸(xi)(xi)力，牽(qian)引(yin)電磁(ci)(ci)鐵(tie)一(yi)般采用(yong)吸(xi)(xi)引(yin)特性比較平(ping)坦的(de)(de)甲殼(ke)式結構。其內部(bu)裝(zhuang)有鐵(tie)心、銜(xian)鐵(tie)和(he)(he)勵(li)磁(ci)(ci)線圈。使用(yong)時，將(jiang)鐵(tie)心固定在機(ji)械裝(zhuang)置(zhi)(zhi)的(de)(de)靜(jing)止(zhi)部(bu)件上，銜(xian)鐵(tie)則連接在牽(qian)引(yin)桿上。當勵(li)磁(ci)(ci)繞組通電后，鐵(tie)心被磁(ci)(ci)化，產生電磁(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)銜(xian)鐵(tie)，后者則通過牽(qian)引(yin)桿來操縱所控(kong)制(zhi)的(de)(de)機(ji)械裝(zhuang)置(zhi)(zhi)的(de)(de)機(ji)構。為了適(shi)應不(bu)(bu)同(tong)控(kong)制(zhi)對象(xiang)的(de)(de)需要(yao)(yao)，牽(qian)引(yin)電磁(ci)(ci)鐵(tie)有拉動式和(he)(he)推動式兩種(zhong)，但都不(bu)(bu)具備復位裝(zhuang)置(zhi)(zhi)。牽(qian)引(yin)電磁(ci)(ci)鐵(tie)的(de)(de)主要(yao)(yao)技術(shu)指標為一(yi)定行(xing)程下(xia)的(de)(de)電磁(ci)(ci)吸(xi)(xi)力、操作頻(pin)率(lv)和(he)(he)壽命。

制動電磁鐵

作(zuo)(zuo)機(ji)械(xie)制動(dong)(dong)用(yong)的(de)一(yi)種電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。主(zhu)要用(yong)于(yu)電(dian)(dian)(dian)(dian)(dian)力驅動(dong)(dong)裝置(zhi)和(he)起(qi)重運輸設(she)備中(zhong)，并(bing)(bing)與(yu)制動(dong)(dong)器(qi)配合使用(yong)，使電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)準確(que)停(ting)(ting)車和(he)懸吊著的(de)重物(wu)不致墜落。制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)按銜(xian)鐵(tie)行(xing)(xing)(xing)程(cheng)(cheng)分(fen)為長行(xing)(xing)(xing)程(cheng)(cheng)和(he)短(duan)行(xing)(xing)(xing)程(cheng)(cheng)兩類(lei)(lei);按勵磁(ci)(ci)(ci)方式(shi)(shi)分(fen)為直流(liu)和(he)交流(liu)、并(bing)(bing)勵和(he)串勵以(yi)及單相(xiang)和(he)三相(xiang)等種類(lei)(lei)。制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)工作(zuo)(zuo)原理是：當電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)繞組通(tong)電(dian)(dian)(dian)(dian)(dian)后，銜(xian)鐵(tie)被吸向(xiang)鐵(tie)心(xin)，并(bing)(bing)通(tong)過制動(dong)(dong)器(qi)中(zhong)的(de)停(ting)(ting)檔壓(ya)迫制動(dong)(dong)桿，使之移動(dong)(dong)，從而(er)迫使制動(dong)(dong)器(qi)松閘。切斷線圈電(dian)(dian)(dian)(dian)(dian)源后，制動(dong)(dong)桿在彈簧(huang)作(zuo)(zuo)用(yong)下(xia)使銜(xian)鐵(tie)脫離磁(ci)(ci)(ci)軛，而(er)制動(dong)(dong)器(qi)則將機(ji)構剎(cha)住。制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)主(zhu)要技術(shu)參(can)數是行(xing)(xing)(xing)程(cheng)(cheng)、一(yi)定行(xing)(xing)(xing)程(cheng)(cheng)下(xia)的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸力、操(cao)(cao)作(zuo)(zuo)頻率(lv)(lv)(lv)和(he)通(tong)電(dian)(dian)(dian)(dian)(dian)持續(xu)率(lv)(lv)(lv)。操(cao)(cao)作(zuo)(zuo)頻率(lv)(lv)(lv)是指每(mei)(mei)小時(shi)(shi)操(cao)(cao)作(zuo)(zuo)的(de)次數;通(tong)電(dian)(dian)(dian)(dian)(dian)持續(xu)率(lv)(lv)(lv)是指每(mei)(mei)次通(tong)電(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間與(yu)每(mei)(mei)次通(tong)電(dian)(dian)(dian)(dian)(dian)及不通(tong)電(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間之和(he)的(de)百分(fen)比。使用(yong)中(zhong)，制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)與(yu)瓦(wa)式(shi)(shi)制動(dong)(dong)器(qi)相(xiang)配合時(shi)(shi)用(yong)短(duan)行(xing)(xing)(xing)程(cheng)(cheng)類(lei)(lei);與(yu)皮帶(dai)制動(dong)(dong)器(qi)相(xiang)配合時(shi)(shi)用(yong)長行(xing)(xing)(xing)程(cheng)(cheng)類(lei)(lei)。制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)過液壓(ya)方式(shi)(shi)將電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)力傳遞給制動(dong)(dong)機(ji)構的(de)稱液壓(ya)制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。

閥用電磁鐵

供遠距離操作各(ge)種液壓、氣動(dong)(dong)系統閥門的(de)電(dian)(dian)(dian)磁鐵(tie)(tie)。常用于各(ge)種金屬(shu)切削機床中。閥用電(dian)(dian)(dian)磁鐵(tie)(tie)不設復位(wei)裝置，而由(you)閥體(ti)(ti)中的(de)彈簧使(shi)之復位(wei)。當電(dian)(dian)(dian)磁鐵(tie)(tie)的(de)勵(li)磁繞組(zu)通過(guo)電(dian)(dian)(dian)流時，電(dian)(dian)(dian)磁吸力即(ji)克服彈簧阻力，使(shi)閥體(ti)(ti)的(de)推桿(gan)移(yi)動(dong)(dong)，將閥門開啟;當勵(li)磁繞組(zu)斷電(dian)(dian)(dian)后，在復位(wei)彈簧作用下(xia)，閥體(ti)(ti)推桿(gan)便推動(dong)(dong)銜(xian)鐵(tie)(tie)，使(shi)其(qi)(qi)移(yi)動(dong)(dong)額定行程處，閥門關閉。閥用電(dian)(dian)(dian)磁鐵(tie)(tie)分為(wei)濕式(shi)和(he)干式(shi)兩種。濕式(shi)閥用電(dian)(dian)(dian)磁鐵(tie)(tie)的(de)銜(xian)鐵(tie)(tie)在液壓油(you)中工作，由(you)于油(you)的(de)冷卻作用，使(shi)其(qi)(qi)與具(ju)有相同吸力的(de)電(dian)(dian)(dian)磁鐵(tie)(tie)相比，有較小(xiao)的(de)尺寸(cun)。

電磁鐵的應用

門(men)禁：為什么門(men)禁可以(yi)(yi)在沒刷卡(ka)時把門(men)牢牢的(de)(de)“抓住(zhu)”？原(yuan)來單元門(men)是由鋼材料(liao)做成(cheng)的(de)(de)，那個金屬體(ti)在通電(dian)(dian)時可以(yi)(yi)產(chan)生強大的(de)(de)磁(ci)場，產(chan)生的(de)(de)磁(ci)力能把門(men)牢牢的(de)(de)吸(xi)住(zhu)，而(er)刷卡(ka)的(de)(de)瞬間(jian)，切(qie)斷電(dian)(dian)流，金屬體(ti)失(shi)去磁(ci)性，我們就可以(yi)(yi)打開(kai)門(men)了。那個金屬體(ti)其實是一(yi)塊電(dian)(dian)磁(ci)鐵。

電(dian)(dian)(dian)磁起(qi)(qi)重(zhong)機(ji)：最(zui)直接的應用之(zhi)一是電(dian)(dian)(dian)磁起(qi)(qi)重(zhong)機(ji)。電(dian)(dian)(dian)磁鐵安裝(zhuang)在吊車上，通電(dian)(dian)(dian)后(hou)吸起(qi)(qi)大量鋼鐵，移動到另一個位(wei)置后(hou)切斷電(dian)(dian)(dian)流，鋼鐵被放下，免去(qu)了打捆的麻(ma)煩。大型電(dian)(dian)(dian)磁起(qi)(qi)重(zhong)機(ji)一次可以吊起(qi)(qi)幾噸鋼材。

在電(dian)動機(ji)(ji)、發電(dian)機(ji)(ji)、電(dian)鈴(ling)和電(dian)磁(ci)(ci)繼(ji)電(dian)器里(li)(li)也(ye)用到電(dian)磁(ci)(ci)鐵(tie)。全自動洗衣機(ji)(ji)的(de)進水、排水閥(fa)門(men)，衛生間里(li)(li)感應式(shi)沖水器的(de)閥(fa)門(men)，也(ye)都是(shi)由電(dian)磁(ci)(ci)鐵(tie)控制的(de)。

電磁(ci)鐵的另一個應用是產生(sheng)強磁(ci)場(chang)。現代技(ji)術中很多(duo)地方(fang)需要的強磁(ci)場(chang)都(dou)由電磁(ci)鐵提供，如大型電動機、發電機、磁(ci)療(liao)設備等。