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。這實際上是福建電磁鐵原理(li)的最初發現。1823年，斯特金(jin)也(ye)做了一(yi)次類似的實驗：他在(zai)一(yi)根并非是(shi)磁(ci)(ci)鐵(tie)(tie)棒(bang)(bang)的U型(xing)(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)繞(rao)(rao)了18圈(quan)銅裸(luo)線，當(dang)銅線與伏打電池接通時，繞(rao)(rao)在(zai)U型(xing)(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)的銅線圈(quan)即產(chan)生了密集的磁(ci)(ci)場，這(zhe)樣就使(shi)U型(xing)(xing)鐵(tie)(tie)棒(bang)(bang)變成了一(yi)塊(kuai)“電磁(ci)(ci)鐵(tie)(tie)”。這(zhe)種電磁(ci)(ci)鐵(tie)(tie)上(shang)的磁(ci)(ci)能(neng)要比永磁(ci)(ci)能(neng)大(da)放多倍，它能(neng)吸(xi)起比它重20倍的鐵(tie)(tie)塊(kuai)，而當(dang)電源切斷后，U型(xing)(xing)鐵(tie)(tie)棒(bang)(bang)就什么鐵(tie)(tie)塊(kuai)也(ye)吸(xi)不住，重新成為一(yi)根普(pu)通的鐵(tie)(tie)棒(bang)(bang)。

斯特金的電(dian)磁鐵發(fa)明(ming)，使人(ren)們看(kan)到(dao)了把電(dian)能轉化為磁能的光明(ming)前景，這一發(fa)明(ming)很快在英國、美國以及西歐一些沿海國家傳播開來。

1829年，美國電(dian)學家亨(heng)利對斯特金(jin)電(dian)磁(ci)鐵(tie)裝置進(jin)行了一些革新(xin)，絕(jue)緣(yuan)導線(xian)代替裸銅導線(xian)，因此不必擔心被(bei)銅導線(xian)過分靠近(jin)而(er)短路。由(you)于導線(xian)有了絕(jue)緣(yuan)層，就(jiu)可以將它(ta)們一圈圈地緊(jin)緊(jin)地繞在(zai)一起，由(you)于線(xian)圈越密集(ji)，產(chan)生的磁(ci)場就(jiu)越強，這樣就(jiu)大(da)(da)大(da)(da)提高了把(ba)電(dian)能(neng)轉化為磁(ci)能(neng)的能(neng)力。到了1831年，亨(heng)利試(shi)制出了一塊(kuai)更新(xin)的電(dian)磁(ci)鐵(tie)，雖然(ran)它(ta)的體積并不大(da)(da)，但它(ta)能(neng)吸起1噸重的鐵(tie)塊(kuai)。

電(dian)磁(ci)(ci)鐵(tie)(tie)內部帶有(you)鐵(tie)(tie)心的(de)(de)(de)、利用通有(you)電(dian)流(liu)的(de)(de)(de)線(xian)圈使其像磁(ci)(ci)鐵(tie)(tie)一樣具有(you)磁(ci)(ci)性(xing)的(de)(de)(de)裝置叫做電(dian)磁(ci)(ci)鐵(tie)(tie)，通常制(zhi)成條形(xing)或蹄(ti)形(xing)。鐵(tie)(tie)心要用容易(yi)磁(ci)(ci)化，又容易(yi)消(xiao)失磁(ci)(ci)性(xing)的(de)(de)(de)軟鐵(tie)(tie)或硅鋼(gang)來制(zhi)做。這樣的(de)(de)(de)電(dian)磁(ci)(ci)鐵(tie)(tie)在通電(dian)時有(you)磁(ci)(ci)性(xing)，斷(duan)電(dian)后就隨之消(xiao)失。 電(dian)磁(ci)(ci)鐵(tie)(tie)有(you)許(xu)多優點(dian)：電(dian)磁(ci)(ci)鐵(tie)(tie)磁(ci)(ci)性(xing)的(de)(de)(de)有(you)無，可以用通、斷(duan)電(dian)流(liu)控(kong)制(zhi)。磁(ci)(ci)性(xing)的(de)(de)(de)大(da)小可以用電(dian)流(liu)的(de)(de)(de)強弱或線(xian)圈的(de)(de)(de)匝數來控(kong)制(zhi)。

電磁鐵的主要特點

1、采用全(quan)密(mi)封結構，防潮性能(neng)好。

2、經計算機優化設計，結(jie)構合(he)理、自重輕、吸力大、能(neng)耗低。

3、勵磁線(xian)圈經特別工藝處理，提高了線(xian)圈的電(dian)器和機械性能，絕緣資料(liao)熱等級到達C級，運用壽命長。

4、普通型電磁(ci)鐵的額定通電持(chi)續(xu)率由曩昔的50%提(ti)高到60%，提(ti)高了電磁(ci)鐵的運用功率。

5、超高溫(wen)型(xing)電磁鐵采用(yong)獨特隔熱方式(shi)，其間被吸物溫(wen)度有曩(nang)昔的600℃提高700℃，擴大了電磁鐵的適用(yong)范圍。

6、裝置(zhi)、運轉、保(bao)護簡潔。

電磁鐵工作原理

將電(dian)(dian)磁(ci)(ci)(ci)(ci)能(neng)變換為機械能(neng)以實現吸(xi)合作功的(de)一種電(dian)(dian)器。通(tong)常由(you)軟磁(ci)(ci)(ci)(ci)材(cai)料制成(cheng)的(de)鐵(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)和(he)勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)組(zu)成(cheng)。當(dang)勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)通(tong)電(dian)(dian)時，繞(rao)組(zu)周圍產生(sheng)磁(ci)(ci)(ci)(ci)場(chang)，鐵(tie)(tie)(tie)心磁(ci)(ci)(ci)(ci)化，并產生(sheng)電(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力吸(xi)引銜(xian)鐵(tie)(tie)(tie)，使之(zhi)運(yun)動(dong)作功。電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)主要用(yong)于(yu)操動(dong)、牽引機械裝置，以達到預期的(de)目的(de)。工(gong)業上(shang)常用(yong)的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)有(you)制動(dong)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、牽引電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、起重電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)和(he)閥(fa)用(yong)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。此外，屬于(yu)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)類的(de)還有(you)用(yong)以傳遞或(huo)隔斷兩軸間的(de)機械聯系的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)聯軸器;用(yong)在機床工(gong)作臺上(shang)以吸(xi)牢磁(ci)(ci)(ci)(ci)性(xing)材(cai)料工(gong)件的(de)電(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)盤;供高(gao)能(neng)物理、核(he)聚變研究(jiu)、磁(ci)(ci)(ci)(ci)流(liu)體發(fa)電(dian)(dian)和(he)高(gao)速懸浮(fu)列車等(deng)方面使用(yong)的(de)、能(neng)產生(sheng)高(gao)達數十特（斯拉）的(de)磁(ci)(ci)(ci)(ci)通(tong)密度而幾乎不(bu)消耗繞(rao)組(zu)功率的(de)超導電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。

起重電磁鐵

用(yong)(yong)來(lai)吊運和(he)裝(zhuang)卸鐵(tie)(tie)磁(ci)(ci)(ci)性(xing)物(wu)(wu)體(ti)的電磁(ci)(ci)(ci)鐵(tie)(tie)。工業上(shang)常(chang)(chang)用(yong)(yong)以(yi)吊運或裝(zhuang)卸鐵(tie)(tie)礦石、鐵(tie)(tie)砂、廢鋼鐵(tie)(tie)、鋼錠、鋼軌以(yi)及各種鋼材和(he)鋼質工件。起(qi)重(zhong)電磁(ci)(ci)(ci)鐵(tie)(tie)通常(chang)(chang)做成(cheng)圓盤(pan)形或矩形，并帶有內(nei)磁(ci)(ci)(ci)極和(he)外磁(ci)(ci)(ci)極。當(dang)勵磁(ci)(ci)(ci)繞(rao)組通電后，內(nei)外磁(ci)(ci)(ci)極均被磁(ci)(ci)(ci)化，吸引鋼質材料或工件（相當(dang)于(yu)一般電磁(ci)(ci)(ci)鐵(tie)(tie)中的銜鐵(tie)(tie)），形成(cheng)一個(ge)閉(bi)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)極與(yu)被吸引物(wu)(wu)體(ti)間的機械撞擊所損傷，起(qi)重(zhong)電磁(ci)(ci)(ci)鐵(tie)(tie)通常(chang)(chang)采用(yong)(yong)甲殼式(shi)結構，并且采用(yong)(yong)直流(liu)勵磁(ci)(ci)(ci)。

牽引電磁鐵

供(gong)牽(qian)(qian)引(yin)和(he)推斥機械(xie)(xie)裝置(zhi)用(yong)(yong)的(de)(de)一(yi)種(zhong)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。主(zhu)要(yao)用(yong)(yong)于各種(zhong)自動設備(bei)中(zhong)，以實(shi)現遠距(ju)離控制。為(wei)了(le)能夠在(zai)長行程(cheng)下(xia)獲得較大(da)的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)吸力，牽(qian)(qian)引(yin)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)一(yi)般采用(yong)(yong)吸引(yin)特性比較平坦(tan)的(de)(de)甲(jia)殼式結(jie)構。其(qi)內部裝有鐵(tie)(tie)心、銜鐵(tie)(tie)和(he)勵磁(ci)(ci)(ci)線圈(quan)。使用(yong)(yong)時，將鐵(tie)(tie)心固定在(zai)機械(xie)(xie)裝置(zhi)的(de)(de)靜止部件上(shang)，銜鐵(tie)(tie)則(ze)連接在(zai)牽(qian)(qian)引(yin)桿上(shang)。當勵磁(ci)(ci)(ci)繞(rao)組(zu)通電(dian)(dian)后，鐵(tie)(tie)心被(bei)磁(ci)(ci)(ci)化，產生電(dian)(dian)磁(ci)(ci)(ci)吸力吸引(yin)銜鐵(tie)(tie)，后者則(ze)通過牽(qian)(qian)引(yin)桿來操(cao)縱所控制的(de)(de)機械(xie)(xie)裝置(zhi)的(de)(de)機構。為(wei)了(le)適應(ying)不同(tong)控制對象的(de)(de)需要(yao)，牽(qian)(qian)引(yin)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)有拉動式和(he)推動式兩種(zhong)，但都不具備(bei)復位裝置(zhi)。牽(qian)(qian)引(yin)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)主(zhu)要(yao)技術指標為(wei)一(yi)定行程(cheng)下(xia)的(de)(de)電(dian)(dian)磁(ci)(ci)(ci)吸力、操(cao)作頻(pin)率和(he)壽命。

制動電磁鐵

作(zuo)(zuo)機械制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)用(yong)的(de)(de)(de)一種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)。主要用(yong)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力(li)驅動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)裝置和(he)起重運輸設備中，并與(yu)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器配合使(shi)用(yong)，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)機準確停車和(he)懸吊著的(de)(de)(de)重物不致墜(zhui)落。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)按銜鐵(tie)行(xing)(xing)程(cheng)(cheng)(cheng)分(fen)為(wei)長(chang)行(xing)(xing)程(cheng)(cheng)(cheng)和(he)短行(xing)(xing)程(cheng)(cheng)(cheng)兩類(lei);按勵(li)(li)磁(ci)方式(shi)分(fen)為(wei)直流和(he)交(jiao)流、并勵(li)(li)和(he)串勵(li)(li)以及單相和(he)三相等種(zhong)類(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)的(de)(de)(de)工作(zuo)(zuo)原(yuan)理是(shi)：當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)的(de)(de)(de)繞組通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)后，銜鐵(tie)被吸向鐵(tie)心，并通(tong)過制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器中的(de)(de)(de)停檔壓(ya)(ya)迫制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿，使(shi)之移動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)，從而迫使(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器松閘。切斷線圈(quan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿在彈簧作(zuo)(zuo)用(yong)下使(shi)銜鐵(tie)脫離(li)磁(ci)軛(e)，而制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器則(ze)將機構剎住。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)的(de)(de)(de)主要技術參數是(shi)行(xing)(xing)程(cheng)(cheng)(cheng)、一定行(xing)(xing)程(cheng)(cheng)(cheng)下的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)吸力(li)、操作(zuo)(zuo)頻率和(he)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率。操作(zuo)(zuo)頻率是(shi)指每小時操作(zuo)(zuo)的(de)(de)(de)次(ci)數;通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率是(shi)指每次(ci)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間與(yu)每次(ci)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)及不通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時間之和(he)的(de)(de)(de)百分(fen)比。使(shi)用(yong)中，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)與(yu)瓦式(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器相配合時用(yong)短行(xing)(xing)程(cheng)(cheng)(cheng)類(lei);與(yu)皮帶制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)器相配合時用(yong)長(chang)行(xing)(xing)程(cheng)(cheng)(cheng)類(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)通(tong)過液(ye)壓(ya)(ya)方式(shi)將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)傳(chuan)遞給制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)機構的(de)(de)(de)稱液(ye)壓(ya)(ya)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵(tie)。

閥用電磁鐵

供遠距(ju)離操(cao)作各種(zhong)液壓、氣動(dong)系統(tong)閥(fa)門(men)的(de)(de)電(dian)(dian)磁(ci)鐵(tie)。常用(yong)(yong)于(yu)各種(zhong)金屬切削機床中。閥(fa)用(yong)(yong)電(dian)(dian)磁(ci)鐵(tie)不(bu)設復(fu)位(wei)裝置，而由(you)閥(fa)體中的(de)(de)彈簧使之復(fu)位(wei)。當電(dian)(dian)磁(ci)鐵(tie)的(de)(de)勵(li)磁(ci)繞組通(tong)過電(dian)(dian)流時(shi)，電(dian)(dian)磁(ci)吸力即(ji)克服彈簧阻力，使閥(fa)體的(de)(de)推(tui)桿移(yi)動(dong)，將閥(fa)門(men)開啟(qi);當勵(li)磁(ci)繞組斷電(dian)(dian)后(hou)，在(zai)復(fu)位(wei)彈簧作用(yong)(yong)下，閥(fa)體推(tui)桿便推(tui)動(dong)銜(xian)鐵(tie)，使其(qi)移(yi)動(dong)額(e)定行程處，閥(fa)門(men)關閉。閥(fa)用(yong)(yong)電(dian)(dian)磁(ci)鐵(tie)分為(wei)濕(shi)式和(he)干式兩種(zhong)。濕(shi)式閥(fa)用(yong)(yong)電(dian)(dian)磁(ci)鐵(tie)的(de)(de)銜(xian)鐵(tie)在(zai)液壓油中工作，由(you)于(yu)油的(de)(de)冷卻作用(yong)(yong)，使其(qi)與具有相(xiang)同吸力的(de)(de)電(dian)(dian)磁(ci)鐵(tie)相(xiang)比，有較小的(de)(de)尺寸。

電磁鐵的應用

門(men)禁：為什么門(men)禁可(ke)以(yi)在沒刷(shua)卡時(shi)把門(men)牢(lao)牢(lao)的(de)(de)“抓(zhua)住(zhu)”？原來單元門(men)是(shi)由鋼材料(liao)做成的(de)(de)，那(nei)個(ge)(ge)金屬(shu)體在通電(dian)時(shi)可(ke)以(yi)產生(sheng)強(qiang)大的(de)(de)磁(ci)場，產生(sheng)的(de)(de)磁(ci)力能把門(men)牢(lao)牢(lao)的(de)(de)吸住(zhu)，而刷(shua)卡的(de)(de)瞬間(jian)，切斷電(dian)流，金屬(shu)體失去(qu)磁(ci)性，我們就可(ke)以(yi)打開門(men)了。那(nei)個(ge)(ge)金屬(shu)體其實(shi)是(shi)一塊電(dian)磁(ci)鐵。

電(dian)磁(ci)起重機：最直接(jie)的(de)應用之一是電(dian)磁(ci)起重機。電(dian)磁(ci)鐵安(an)裝(zhuang)在吊(diao)車上，通電(dian)后吸起大量鋼(gang)鐵，移動到另一個位置后切斷電(dian)流(liu)，鋼(gang)鐵被放下，免去了(le)打捆的(de)麻煩。大型電(dian)磁(ci)起重機一次可以(yi)吊(diao)起幾噸鋼(gang)材。

在電(dian)(dian)動機(ji)、發(fa)電(dian)(dian)機(ji)、電(dian)(dian)鈴和電(dian)(dian)磁(ci)(ci)繼電(dian)(dian)器里(li)也用到電(dian)(dian)磁(ci)(ci)鐵(tie)。全自動洗衣機(ji)的(de)進水、排水閥門(men)，衛生間(jian)里(li)感(gan)應式沖水器的(de)閥門(men)，也都是由電(dian)(dian)磁(ci)(ci)鐵(tie)控制的(de)。

電(dian)磁(ci)(ci)鐵(tie)的(de)另一個應用是產(chan)生強磁(ci)(ci)場(chang)。現代技術(shu)中很多地方需要的(de)強磁(ci)(ci)場(chang)都(dou)由電(dian)磁(ci)(ci)鐵(tie)提(ti)供(gong)，如(ru)大型電(dian)動機、發電(dian)機、磁(ci)(ci)療設備等。