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。這實際上是武漢電磁鐵原理(li)的(de)(de)最初發現(xian)。1823年，斯特金也做(zuo)了一(yi)(yi)次類(lei)似(si)的(de)(de)實驗：他在(zai)一(yi)(yi)根并(bing)非是磁(ci)鐵(tie)(tie)(tie)棒的(de)(de)U型(xing)(xing)鐵(tie)(tie)(tie)棒上(shang)(shang)繞了18圈銅(tong)裸線(xian)，當(dang)(dang)銅(tong)線(xian)與伏打(da)電池接通時(shi)，繞在(zai)U型(xing)(xing)鐵(tie)(tie)(tie)棒上(shang)(shang)的(de)(de)銅(tong)線(xian)圈即產生了密集的(de)(de)磁(ci)場，這樣(yang)就使U型(xing)(xing)鐵(tie)(tie)(tie)棒變成(cheng)了一(yi)(yi)塊“電磁(ci)鐵(tie)(tie)(tie)”。這種(zhong)電磁(ci)鐵(tie)(tie)(tie)上(shang)(shang)的(de)(de)磁(ci)能(neng)(neng)要(yao)比永磁(ci)能(neng)(neng)大放多(duo)倍，它能(neng)(neng)吸(xi)起(qi)比它重(zhong)20倍的(de)(de)鐵(tie)(tie)(tie)塊，而(er)當(dang)(dang)電源切斷后，U型(xing)(xing)鐵(tie)(tie)(tie)棒就什么鐵(tie)(tie)(tie)塊也吸(xi)不住，重(zhong)新成(cheng)為一(yi)(yi)根普通的(de)(de)鐵(tie)(tie)(tie)棒。

斯(si)特金的(de)電(dian)磁(ci)鐵(tie)發明，使(shi)人(ren)們(men)看(kan)到了把電(dian)能轉化(hua)為磁(ci)能的(de)光明前景，這一發明很快在英國(guo)(guo)、美國(guo)(guo)以及西(xi)歐(ou)一些沿海國(guo)(guo)家傳播(bo)開來。

1829年，美國電(dian)學家亨(heng)利對斯(si)特金(jin)電(dian)磁鐵裝置進行(xing)了(le)一(yi)(yi)些革新(xin)，絕緣導(dao)(dao)(dao)線代替(ti)裸銅導(dao)(dao)(dao)線，因此不(bu)必(bi)擔心(xin)被銅導(dao)(dao)(dao)線過分靠近而短路(lu)。由于(yu)(yu)導(dao)(dao)(dao)線有了(le)絕緣層，就可以將它們一(yi)(yi)圈(quan)圈(quan)地(di)緊緊地(di)繞在(zai)一(yi)(yi)起，由于(yu)(yu)線圈(quan)越(yue)密集，產生的磁場就越(yue)強，這樣(yang)就大大提(ti)高了(le)把電(dian)能(neng)轉(zhuan)化為磁能(neng)的能(neng)力。到了(le)1831年，亨(heng)利試制出了(le)一(yi)(yi)塊(kuai)更新(xin)的電(dian)磁鐵，雖然它的體積并(bing)不(bu)大，但它能(neng)吸起1噸重的鐵塊(kuai)。

電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)內部帶有鐵(tie)心的(de)、利用(yong)通有電(dian)(dian)流(liu)的(de)線圈使其像磁(ci)(ci)(ci)鐵(tie)一(yi)樣具有磁(ci)(ci)(ci)性的(de)裝(zhuang)置叫做電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)，通常制成條形或蹄(ti)形。鐵(tie)心要用(yong)容(rong)易磁(ci)(ci)(ci)化，又容(rong)易消失(shi)磁(ci)(ci)(ci)性的(de)軟(ruan)鐵(tie)或硅(gui)鋼來制做。這樣的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)在(zai)通電(dian)(dian)時有磁(ci)(ci)(ci)性，斷(duan)電(dian)(dian)后就隨之(zhi)消失(shi)。 電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)有許多優(you)點：電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)磁(ci)(ci)(ci)性的(de)有無(wu)，可以用(yong)通、斷(duan)電(dian)(dian)流(liu)控制。磁(ci)(ci)(ci)性的(de)大小(xiao)可以用(yong)電(dian)(dian)流(liu)的(de)強弱或線圈的(de)匝數來控制。

電磁鐵的主要特點

1、采(cai)用全密封結構，防潮性能好。

2、經計(ji)算機優化設計(ji)，結構(gou)合理、自(zi)重輕(qing)、吸力大、能耗低。

3、勵磁線圈經特別工藝處(chu)理(li)，提(ti)高了線圈的電器和(he)機械性能(neng)，絕緣資料熱(re)等級到達C級，運用壽命長(chang)。

4、普(pu)通(tong)型(xing)電磁(ci)鐵的(de)額(e)定(ding)通(tong)電持續(xu)率(lv)由曩昔的(de)50%提(ti)高到60%，提(ti)高了(le)電磁(ci)鐵的(de)運用功率(lv)。

5、超高(gao)溫型電磁(ci)鐵采用獨特隔熱(re)方式(shi)，其間被吸物溫度有曩昔的600℃提(ti)高(gao)700℃，擴大(da)了(le)電磁(ci)鐵的適用范圍(wei)。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)能變換(huan)為機(ji)械能以(yi)實現吸(xi)(xi)合作(zuo)功的(de)一種電(dian)(dian)(dian)(dian)(dian)器(qi)。通常(chang)由軟磁(ci)(ci)(ci)材料(liao)制成(cheng)的(de)鐵(tie)心、銜鐵(tie)和(he)勵(li)磁(ci)(ci)(ci)繞(rao)組組成(cheng)。當勵(li)磁(ci)(ci)(ci)繞(rao)組通電(dian)(dian)(dian)(dian)(dian)時，繞(rao)組周圍產生(sheng)磁(ci)(ci)(ci)場(chang)，鐵(tie)心磁(ci)(ci)(ci)化，并產生(sheng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引銜鐵(tie)，使之(zhi)運動(dong)(dong)作(zuo)功。電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)主要用于操動(dong)(dong)、牽引機(ji)械裝置，以(yi)達到預期的(de)目的(de)。工業上常(chang)用的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)有制動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)、牽引電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)、起重電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)和(he)閥用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)等(deng)(deng)(deng)。此外，屬(shu)于電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)類的(de)還(huan)有用以(yi)傳遞或(huo)隔斷兩軸間的(de)機(ji)械聯(lian)系的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)聯(lian)軸器(qi);用在機(ji)床工作(zuo)臺上以(yi)吸(xi)(xi)牢(lao)磁(ci)(ci)(ci)性材料(liao)工件(jian)的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)盤;供高(gao)能物(wu)理、核(he)聚(ju)變研究(jiu)、磁(ci)(ci)(ci)流體發電(dian)(dian)(dian)(dian)(dian)和(he)高(gao)速懸浮(fu)列車(che)等(deng)(deng)(deng)方面使用的(de)、能產生(sheng)高(gao)達數十特（斯(si)拉）的(de)磁(ci)(ci)(ci)通密度而(er)幾乎不消耗繞(rao)組功率的(de)超導電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)等(deng)(deng)(deng)。

起重電磁鐵

用(yong)來吊(diao)運和(he)裝卸鐵(tie)(tie)(tie)磁(ci)(ci)(ci)性(xing)物(wu)(wu)體的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)。工(gong)業上常用(yong)以吊(diao)運或裝卸鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂、廢鋼(gang)(gang)鐵(tie)(tie)(tie)、鋼(gang)(gang)錠、鋼(gang)(gang)軌以及各種鋼(gang)(gang)材(cai)和(he)鋼(gang)(gang)質(zhi)工(gong)件。起重電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常做(zuo)成圓盤形(xing)(xing)或矩形(xing)(xing)，并帶有(you)內(nei)磁(ci)(ci)(ci)極和(he)外(wai)(wai)磁(ci)(ci)(ci)極。當勵(li)磁(ci)(ci)(ci)繞組通電(dian)(dian)后，內(nei)外(wai)(wai)磁(ci)(ci)(ci)極均被磁(ci)(ci)(ci)化，吸引鋼(gang)(gang)質(zhi)材(cai)料或工(gong)件（相(xiang)當于一般(ban)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)中的(de)(de)銜(xian)鐵(tie)(tie)(tie)），形(xing)(xing)成一個閉合的(de)(de)磁(ci)(ci)(ci)路。為保護(hu)勵(li)磁(ci)(ci)(ci)繞組，使(shi)之不因磁(ci)(ci)(ci)極與被吸引物(wu)(wu)體間的(de)(de)機械撞擊(ji)所損(sun)傷，起重電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)通常采(cai)用(yong)甲(jia)殼式結構，并且采(cai)用(yong)直流勵(li)磁(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)(yin)和推(tui)斥(chi)機(ji)(ji)械(xie)裝置用(yong)(yong)的(de)(de)(de)一(yi)(yi)種(zhong)(zhong)電磁(ci)鐵(tie)(tie)(tie)。主要(yao)用(yong)(yong)于各種(zhong)(zhong)自動設備中(zhong)，以實現遠距離控制(zhi)。為(wei)了能(neng)夠(gou)在(zai)(zai)長(chang)行程(cheng)下獲得較(jiao)大(da)的(de)(de)(de)電磁(ci)吸(xi)力(li)，牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)一(yi)(yi)般采(cai)用(yong)(yong)吸(xi)引(yin)(yin)特性比(bi)較(jiao)平坦的(de)(de)(de)甲(jia)殼式(shi)結構。其內(nei)部裝有(you)鐵(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)和勵磁(ci)線圈(quan)。使用(yong)(yong)時(shi)，將鐵(tie)(tie)(tie)心固定在(zai)(zai)機(ji)(ji)械(xie)裝置的(de)(de)(de)靜止部件上，銜(xian)鐵(tie)(tie)(tie)則連接在(zai)(zai)牽(qian)引(yin)(yin)桿(gan)上。當勵磁(ci)繞組通電后(hou)，鐵(tie)(tie)(tie)心被(bei)磁(ci)化，產生電磁(ci)吸(xi)力(li)吸(xi)引(yin)(yin)銜(xian)鐵(tie)(tie)(tie)，后(hou)者則通過牽(qian)引(yin)(yin)桿(gan)來操縱所控制(zhi)的(de)(de)(de)機(ji)(ji)械(xie)裝置的(de)(de)(de)機(ji)(ji)構。為(wei)了適應不同(tong)控制(zhi)對象的(de)(de)(de)需(xu)要(yao)，牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)有(you)拉動式(shi)和推(tui)動式(shi)兩種(zhong)(zhong)，但都(dou)不具備復(fu)位裝置。牽(qian)引(yin)(yin)電磁(ci)鐵(tie)(tie)(tie)的(de)(de)(de)主要(yao)技術指標為(wei)一(yi)(yi)定行程(cheng)下的(de)(de)(de)電磁(ci)吸(xi)力(li)、操作頻率和壽命。

制動電磁鐵

作(zuo)機械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)用的(de)(de)(de)一種(zhong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)。主(zhu)要(yao)用于(yu)電(dian)(dian)(dian)(dian)力(li)驅動(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)(he)起重(zhong)(zhong)運輸設備中，并與制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配(pei)合(he)使(shi)(shi)用，使(shi)(shi)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機準確停車和(he)(he)(he)懸吊著的(de)(de)(de)重(zhong)(zhong)物不致墜落。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)按銜(xian)鐵(tie)(tie)行(xing)程(cheng)(cheng)(cheng)分為長(chang)行(xing)程(cheng)(cheng)(cheng)和(he)(he)(he)短(duan)行(xing)程(cheng)(cheng)(cheng)兩(liang)類;按勵磁(ci)(ci)方(fang)式(shi)分為直流和(he)(he)(he)交流、并勵和(he)(he)(he)串勵以及單相(xiang)和(he)(he)(he)三相(xiang)等種(zhong)類。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)的(de)(de)(de)工(gong)作(zuo)原(yuan)理是(shi)(shi)(shi)：當電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)的(de)(de)(de)繞組通(tong)(tong)電(dian)(dian)(dian)(dian)后，銜(xian)鐵(tie)(tie)被吸向鐵(tie)(tie)心，并通(tong)(tong)過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中的(de)(de)(de)停檔壓(ya)迫制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿，使(shi)(shi)之(zhi)移動(dong)(dong)(dong)(dong)(dong)，從而迫使(shi)(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松閘。切(qie)斷線(xian)圈電(dian)(dian)(dian)(dian)源(yuan)后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿在彈簧作(zuo)用下(xia)使(shi)(shi)銜(xian)鐵(tie)(tie)脫離(li)磁(ci)(ci)軛，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則將(jiang)機構剎住(zhu)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)的(de)(de)(de)主(zhu)要(yao)技術參數是(shi)(shi)(shi)行(xing)程(cheng)(cheng)(cheng)、一定(ding)行(xing)程(cheng)(cheng)(cheng)下(xia)的(de)(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)吸力(li)、操作(zuo)頻率(lv)和(he)(he)(he)通(tong)(tong)電(dian)(dian)(dian)(dian)持(chi)(chi)續(xu)率(lv)。操作(zuo)頻率(lv)是(shi)(shi)(shi)指(zhi)每小時操作(zuo)的(de)(de)(de)次數;通(tong)(tong)電(dian)(dian)(dian)(dian)持(chi)(chi)續(xu)率(lv)是(shi)(shi)(shi)指(zhi)每次通(tong)(tong)電(dian)(dian)(dian)(dian)時間與每次通(tong)(tong)電(dian)(dian)(dian)(dian)及不通(tong)(tong)電(dian)(dian)(dian)(dian)時間之(zhi)和(he)(he)(he)的(de)(de)(de)百分比。使(shi)(shi)用中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)與瓦式(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相(xiang)配(pei)合(he)時用短(duan)行(xing)程(cheng)(cheng)(cheng)類;與皮帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相(xiang)配(pei)合(he)時用長(chang)行(xing)程(cheng)(cheng)(cheng)類。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)通(tong)(tong)過(guo)液(ye)壓(ya)方(fang)式(shi)將(jiang)電(dian)(dian)(dian)(dian)磁(ci)(ci)力(li)傳遞給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)機構的(de)(de)(de)稱(cheng)液(ye)壓(ya)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)。

閥用電磁鐵

供遠(yuan)距離操作(zuo)(zuo)(zuo)各(ge)種液壓(ya)、氣動(dong)系統閥(fa)門(men)的(de)電(dian)(dian)磁(ci)(ci)鐵。常用(yong)于各(ge)種金屬(shu)切削機床中(zhong)。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)鐵不設(she)復位(wei)裝置，而由閥(fa)體中(zhong)的(de)彈(dan)簧(huang)使之復位(wei)。當(dang)電(dian)(dian)磁(ci)(ci)鐵的(de)勵(li)磁(ci)(ci)繞(rao)組通過電(dian)(dian)流(liu)時，電(dian)(dian)磁(ci)(ci)吸力(li)即克服彈(dan)簧(huang)阻力(li)，使閥(fa)體的(de)推桿移動(dong)，將閥(fa)門(men)開啟;當(dang)勵(li)磁(ci)(ci)繞(rao)組斷電(dian)(dian)后(hou)，在復位(wei)彈(dan)簧(huang)作(zuo)(zuo)(zuo)用(yong)下，閥(fa)體推桿便推動(dong)銜鐵，使其移動(dong)額定行程處，閥(fa)門(men)關閉(bi)。閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)鐵分為濕式(shi)和干式(shi)兩種。濕式(shi)閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)鐵的(de)銜鐵在液壓(ya)油(you)(you)中(zhong)工作(zuo)(zuo)(zuo)，由于油(you)(you)的(de)冷(leng)卻作(zuo)(zuo)(zuo)用(yong)，使其與具有相(xiang)同吸力(li)的(de)電(dian)(dian)磁(ci)(ci)鐵相(xiang)比(bi)，有較小(xiao)的(de)尺寸。

電磁鐵的應用

門(men)禁：為什么門(men)禁可(ke)(ke)以在沒刷(shua)卡時把門(men)牢(lao)牢(lao)的(de)(de)“抓住”？原來單元門(men)是(shi)由(you)鋼材料(liao)做成的(de)(de)，那個金(jin)屬體在通電時可(ke)(ke)以產生強大的(de)(de)磁(ci)場，產生的(de)(de)磁(ci)力(li)能(neng)把門(men)牢(lao)牢(lao)的(de)(de)吸住，而刷(shua)卡的(de)(de)瞬間，切斷電流，金(jin)屬體失(shi)去(qu)磁(ci)性，我們(men)就可(ke)(ke)以打開門(men)了。那個金(jin)屬體其實是(shi)一(yi)塊電磁(ci)鐵。

電(dian)(dian)磁(ci)起重(zhong)機(ji)：最(zui)直接的(de)應用之一(yi)是電(dian)(dian)磁(ci)起重(zhong)機(ji)。電(dian)(dian)磁(ci)鐵安裝在(zai)吊車上(shang)，通電(dian)(dian)后(hou)吸起大量(liang)鋼(gang)鐵，移動到(dao)另(ling)一(yi)個位(wei)置后(hou)切斷電(dian)(dian)流，鋼(gang)鐵被放(fang)下(xia)，免去(qu)了打捆(kun)的(de)麻煩。大型電(dian)(dian)磁(ci)起重(zhong)機(ji)一(yi)次可以吊起幾(ji)噸(dun)鋼(gang)材。

在電(dian)動機(ji)(ji)、發電(dian)機(ji)(ji)、電(dian)鈴和電(dian)磁(ci)繼電(dian)器里(li)也用到電(dian)磁(ci)鐵。全自動洗衣機(ji)(ji)的(de)進水、排水閥門(men)(men)，衛(wei)生間里(li)感應式(shi)沖水器的(de)閥門(men)(men)，也都是由電(dian)磁(ci)鐵控制的(de)。

電磁鐵的另一個應用(yong)是(shi)產生(sheng)強磁場。現(xian)代技(ji)術中很多地方需要的強磁場都由電磁鐵提供，如大型(xing)電動(dong)機、發電機、磁療(liao)設備(bei)等。