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。這實際上是蘭州電磁鐵原(yuan)理的(de)(de)(de)最初(chu)發現。1823年(nian)，斯特金(jin)也(ye)做了一(yi)(yi)次(ci)類(lei)似的(de)(de)(de)實驗：他在一(yi)(yi)根并非是磁(ci)鐵(tie)(tie)棒(bang)的(de)(de)(de)U型(xing)(xing)鐵(tie)(tie)棒(bang)上(shang)繞了18圈(quan)銅(tong)裸線，當銅(tong)線與伏打電(dian)(dian)池接通時(shi)，繞在U型(xing)(xing)鐵(tie)(tie)棒(bang)上(shang)的(de)(de)(de)銅(tong)線圈(quan)即產(chan)生(sheng)了密(mi)集的(de)(de)(de)磁(ci)場(chang)，這(zhe)樣就使U型(xing)(xing)鐵(tie)(tie)棒(bang)變成了一(yi)(yi)塊“電(dian)(dian)磁(ci)鐵(tie)(tie)”。這(zhe)種電(dian)(dian)磁(ci)鐵(tie)(tie)上(shang)的(de)(de)(de)磁(ci)能要比(bi)永磁(ci)能大放多倍(bei)，它能吸(xi)起(qi)比(bi)它重20倍(bei)的(de)(de)(de)鐵(tie)(tie)塊，而當電(dian)(dian)源切(qie)斷后，U型(xing)(xing)鐵(tie)(tie)棒(bang)就什(shen)么(me)鐵(tie)(tie)塊也(ye)吸(xi)不住，重新成為一(yi)(yi)根普通的(de)(de)(de)鐵(tie)(tie)棒(bang)。

斯特金的電磁鐵(tie)發(fa)(fa)明，使人們看到了把電能(neng)轉化為磁能(neng)的光明前景(jing)，這一發(fa)(fa)明很快(kuai)在英國、美(mei)國以及(ji)西(xi)歐一些沿海國家傳(chuan)播(bo)開來。

1829年，美國電(dian)學家亨(heng)利對斯特金電(dian)磁鐵裝(zhuang)置進行(xing)了(le)(le)一些革新(xin)，絕緣(yuan)導(dao)(dao)線(xian)代替裸銅導(dao)(dao)線(xian)，因此(ci)不必擔心(xin)被銅導(dao)(dao)線(xian)過分靠近而(er)短路。由于(yu)導(dao)(dao)線(xian)有了(le)(le)絕緣(yuan)層，就可以將它們一圈圈地(di)緊(jin)緊(jin)地(di)繞在一起，由于(yu)線(xian)圈越密(mi)集，產生的(de)(de)(de)磁場就越強，這樣(yang)就大(da)大(da)提高了(le)(le)把電(dian)能轉化為磁能的(de)(de)(de)能力。到(dao)了(le)(le)1831年，亨(heng)利試制(zhi)出了(le)(le)一塊更新(xin)的(de)(de)(de)電(dian)磁鐵，雖然它的(de)(de)(de)體積(ji)并不大(da)，但它能吸起1噸(dun)重的(de)(de)(de)鐵塊。

電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)內部帶有(you)(you)鐵(tie)(tie)心(xin)的(de)、利用(yong)通有(you)(you)電(dian)(dian)流的(de)線(xian)(xian)圈使其像磁(ci)(ci)(ci)鐵(tie)(tie)一樣具有(you)(you)磁(ci)(ci)(ci)性(xing)的(de)裝置叫做電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)，通常制(zhi)成條形(xing)或(huo)蹄形(xing)。鐵(tie)(tie)心(xin)要(yao)用(yong)容易磁(ci)(ci)(ci)化，又容易消失磁(ci)(ci)(ci)性(xing)的(de)軟鐵(tie)(tie)或(huo)硅鋼來(lai)制(zhi)做。這樣的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)在(zai)通電(dian)(dian)時有(you)(you)磁(ci)(ci)(ci)性(xing)，斷電(dian)(dian)后(hou)就隨之消失。 電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)有(you)(you)許(xu)多優點：電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)磁(ci)(ci)(ci)性(xing)的(de)有(you)(you)無，可以用(yong)通、斷電(dian)(dian)流控制(zhi)。磁(ci)(ci)(ci)性(xing)的(de)大小(xiao)可以用(yong)電(dian)(dian)流的(de)強(qiang)弱或(huo)線(xian)(xian)圈的(de)匝數來(lai)控制(zhi)。

電磁鐵的主要特點

1、采(cai)用全密(mi)封結構(gou)，防潮性能好。

2、經(jing)計算機(ji)優化設計，結構(gou)合理、自重輕、吸力大(da)、能耗低(di)。

3、勵(li)磁(ci)線圈經(jing)特別工藝處(chu)理，提高(gao)了線圈的電(dian)器和機械性能，絕緣資料熱等級到達(da)C級，運用(yong)壽命(ming)長。

4、普通型電(dian)磁鐵(tie)的額定(ding)通電(dian)持續率由(you)曩昔的50%提高到60%，提高了電(dian)磁鐵(tie)的運用功率。

5、超高溫型電磁鐵采(cai)用獨特隔(ge)熱方式，其間(jian)被吸物溫度(du)有曩(nang)昔的600℃提高700℃，擴大了(le)電磁鐵的適用范圍(wei)。

6、裝(zhuang)置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)能(neng)變(bian)換(huan)為機械能(neng)以(yi)(yi)實(shi)現吸(xi)合作(zuo)功的(de)(de)一種電(dian)(dian)(dian)器。通(tong)常由軟(ruan)磁(ci)材(cai)料(liao)制成的(de)(de)鐵(tie)心、銜鐵(tie)和(he)勵(li)磁(ci)繞組組成。當(dang)勵(li)磁(ci)繞組通(tong)電(dian)(dian)(dian)時，繞組周圍產(chan)生磁(ci)場，鐵(tie)心磁(ci)化，并產(chan)生電(dian)(dian)(dian)磁(ci)吸(xi)力(li)吸(xi)引銜鐵(tie)，使之(zhi)運動(dong)作(zuo)功。電(dian)(dian)(dian)磁(ci)鐵(tie)主要(yao)用(yong)(yong)于操(cao)動(dong)、牽引機械裝置，以(yi)(yi)達到預期的(de)(de)目的(de)(de)。工業上常用(yong)(yong)的(de)(de)電(dian)(dian)(dian)磁(ci)鐵(tie)有(you)制動(dong)電(dian)(dian)(dian)磁(ci)鐵(tie)、牽引電(dian)(dian)(dian)磁(ci)鐵(tie)、起(qi)重電(dian)(dian)(dian)磁(ci)鐵(tie)和(he)閥用(yong)(yong)電(dian)(dian)(dian)磁(ci)鐵(tie)等。此外(wai)，屬于電(dian)(dian)(dian)磁(ci)鐵(tie)類的(de)(de)還(huan)有(you)用(yong)(yong)以(yi)(yi)傳遞(di)或(huo)隔斷兩軸間(jian)的(de)(de)機械聯(lian)系的(de)(de)電(dian)(dian)(dian)磁(ci)聯(lian)軸器;用(yong)(yong)在機床工作(zuo)臺(tai)上以(yi)(yi)吸(xi)牢磁(ci)性材(cai)料(liao)工件的(de)(de)電(dian)(dian)(dian)磁(ci)吸(xi)盤;供高能(neng)物理、核聚(ju)變(bian)研(yan)究、磁(ci)流體發(fa)電(dian)(dian)(dian)和(he)高速懸浮(fu)列車等方面使用(yong)(yong)的(de)(de)、能(neng)產(chan)生高達數十特(te)（斯拉）的(de)(de)磁(ci)通(tong)密度(du)而(er)幾乎不消(xiao)耗繞組功率的(de)(de)超導(dao)電(dian)(dian)(dian)磁(ci)鐵(tie)等。

起重電磁鐵

用(yong)來吊運(yun)和(he)裝卸(xie)鐵(tie)磁(ci)(ci)(ci)(ci)(ci)(ci)性物(wu)體(ti)的(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)。工業(ye)上常用(yong)以(yi)吊運(yun)或(huo)裝卸(xie)鐵(tie)礦石、鐵(tie)砂(sha)、廢鋼(gang)(gang)(gang)鐵(tie)、鋼(gang)(gang)(gang)錠、鋼(gang)(gang)(gang)軌以(yi)及各種(zhong)鋼(gang)(gang)(gang)材(cai)和(he)鋼(gang)(gang)(gang)質工件。起重(zhong)(zhong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)通(tong)常做成圓(yuan)盤形或(huo)矩形，并(bing)帶(dai)有內磁(ci)(ci)(ci)(ci)(ci)(ci)極和(he)外磁(ci)(ci)(ci)(ci)(ci)(ci)極。當勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組通(tong)電(dian)(dian)(dian)后(hou)，內外磁(ci)(ci)(ci)(ci)(ci)(ci)極均被(bei)磁(ci)(ci)(ci)(ci)(ci)(ci)化，吸引鋼(gang)(gang)(gang)質材(cai)料或(huo)工件（相當于一般電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)中的(de)銜鐵(tie)），形成一個閉合的(de)磁(ci)(ci)(ci)(ci)(ci)(ci)路。為保(bao)護(hu)勵磁(ci)(ci)(ci)(ci)(ci)(ci)繞組，使之不(bu)因磁(ci)(ci)(ci)(ci)(ci)(ci)極與(yu)被(bei)吸引物(wu)體(ti)間的(de)機械撞擊所(suo)損傷，起重(zhong)(zhong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)通(tong)常采(cai)用(yong)甲殼式結(jie)構(gou)，并(bing)且采(cai)用(yong)直(zhi)流(liu)勵磁(ci)(ci)(ci)(ci)(ci)(ci)。

牽引電磁鐵

供牽(qian)引(yin)(yin)和(he)推(tui)斥機(ji)械裝(zhuang)(zhuang)置(zhi)(zhi)用(yong)的(de)(de)(de)(de)一種(zhong)(zhong)(zhong)電(dian)磁(ci)(ci)(ci)(ci)鐵。主(zhu)要用(yong)于各種(zhong)(zhong)(zhong)自動設備中，以實現(xian)遠距離控(kong)(kong)制(zhi)。為(wei)了能夠在長行程(cheng)下(xia)(xia)獲得較大(da)的(de)(de)(de)(de)電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)(li)，牽(qian)引(yin)(yin)電(dian)磁(ci)(ci)(ci)(ci)鐵一般采用(yong)吸(xi)(xi)引(yin)(yin)特性比(bi)較平坦的(de)(de)(de)(de)甲殼式結構。其內部裝(zhuang)(zhuang)有鐵心、銜(xian)鐵和(he)勵磁(ci)(ci)(ci)(ci)線圈(quan)。使用(yong)時，將鐵心固(gu)定在機(ji)械裝(zhuang)(zhuang)置(zhi)(zhi)的(de)(de)(de)(de)靜(jing)止部件上，銜(xian)鐵則(ze)連接在牽(qian)引(yin)(yin)桿上。當勵磁(ci)(ci)(ci)(ci)繞組通電(dian)后(hou)，鐵心被磁(ci)(ci)(ci)(ci)化(hua)，產生電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)(li)吸(xi)(xi)引(yin)(yin)銜(xian)鐵，后(hou)者則(ze)通過(guo)牽(qian)引(yin)(yin)桿來操縱所控(kong)(kong)制(zhi)的(de)(de)(de)(de)機(ji)械裝(zhuang)(zhuang)置(zhi)(zhi)的(de)(de)(de)(de)機(ji)構。為(wei)了適應(ying)不(bu)(bu)同控(kong)(kong)制(zhi)對象的(de)(de)(de)(de)需要，牽(qian)引(yin)(yin)電(dian)磁(ci)(ci)(ci)(ci)鐵有拉動式和(he)推(tui)動式兩種(zhong)(zhong)(zhong)，但都不(bu)(bu)具備復位裝(zhuang)(zhuang)置(zhi)(zhi)。牽(qian)引(yin)(yin)電(dian)磁(ci)(ci)(ci)(ci)鐵的(de)(de)(de)(de)主(zhu)要技術(shu)指標(biao)為(wei)一定行程(cheng)下(xia)(xia)的(de)(de)(de)(de)電(dian)磁(ci)(ci)(ci)(ci)吸(xi)(xi)力(li)(li)、操作頻率和(he)壽命。

制動電磁鐵

作(zuo)機械制(zhi)(zhi)動(dong)(dong)(dong)用的(de)(de)一種(zhong)(zhong)電(dian)(dian)磁鐵(tie)。主要用于(yu)電(dian)(dian)力驅動(dong)(dong)(dong)裝(zhuang)置和起(qi)重運輸設備(bei)中(zhong)，并(bing)(bing)與制(zhi)(zhi)動(dong)(dong)(dong)器配合使(shi)(shi)用，使(shi)(shi)電(dian)(dian)動(dong)(dong)(dong)機準確(que)停車和懸(xuan)吊著(zhu)的(de)(de)重物不致(zhi)墜落。制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)按銜鐵(tie)行(xing)程(cheng)分(fen)為(wei)(wei)長(chang)行(xing)程(cheng)和短(duan)行(xing)程(cheng)兩類(lei);按勵磁方(fang)(fang)式(shi)分(fen)為(wei)(wei)直流和交流、并(bing)(bing)勵和串勵以及(ji)單(dan)相(xiang)和三相(xiang)等種(zhong)(zhong)類(lei)。制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)的(de)(de)工作(zuo)原理(li)是：當電(dian)(dian)磁鐵(tie)的(de)(de)繞組通(tong)電(dian)(dian)后，銜鐵(tie)被吸向(xiang)鐵(tie)心，并(bing)(bing)通(tong)過制(zhi)(zhi)動(dong)(dong)(dong)器中(zhong)的(de)(de)停檔壓(ya)(ya)(ya)迫制(zhi)(zhi)動(dong)(dong)(dong)桿，使(shi)(shi)之移動(dong)(dong)(dong)，從而(er)(er)迫使(shi)(shi)制(zhi)(zhi)動(dong)(dong)(dong)器松閘。切斷線圈電(dian)(dian)源后，制(zhi)(zhi)動(dong)(dong)(dong)桿在彈(dan)簧作(zuo)用下(xia)使(shi)(shi)銜鐵(tie)脫(tuo)離磁軛，而(er)(er)制(zhi)(zhi)動(dong)(dong)(dong)器則將機構剎住。制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)的(de)(de)主要技術參數是行(xing)程(cheng)、一定行(xing)程(cheng)下(xia)的(de)(de)電(dian)(dian)磁吸力、操(cao)作(zuo)頻率(lv)和通(tong)電(dian)(dian)持(chi)續率(lv)。操(cao)作(zuo)頻率(lv)是指每(mei)(mei)小時(shi)(shi)操(cao)作(zuo)的(de)(de)次(ci)數;通(tong)電(dian)(dian)持(chi)續率(lv)是指每(mei)(mei)次(ci)通(tong)電(dian)(dian)時(shi)(shi)間(jian)與每(mei)(mei)次(ci)通(tong)電(dian)(dian)及(ji)不通(tong)電(dian)(dian)時(shi)(shi)間(jian)之和的(de)(de)百分(fen)比。使(shi)(shi)用中(zhong)，制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)與瓦(wa)式(shi)制(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配合時(shi)(shi)用短(duan)行(xing)程(cheng)類(lei);與皮帶制(zhi)(zhi)動(dong)(dong)(dong)器相(xiang)配合時(shi)(shi)用長(chang)行(xing)程(cheng)類(lei)。制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)通(tong)過液壓(ya)(ya)(ya)方(fang)(fang)式(shi)將電(dian)(dian)磁力傳(chuan)遞給(gei)制(zhi)(zhi)動(dong)(dong)(dong)機構的(de)(de)稱(cheng)液壓(ya)(ya)(ya)制(zhi)(zhi)動(dong)(dong)(dong)電(dian)(dian)磁鐵(tie)。

閥用電磁鐵

供遠距離操作各種(zhong)液(ye)壓、氣動(dong)系統(tong)閥門(men)(men)的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用于(yu)各種(zhong)金(jin)屬切削(xue)機(ji)床中(zhong)。閥用電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設(she)復(fu)位裝(zhuang)置，而由(you)閥體中(zhong)的(de)(de)彈簧使(shi)之復(fu)位。當(dang)(dang)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)勵磁(ci)(ci)(ci)繞(rao)組(zu)通過電(dian)(dian)(dian)流時(shi)，電(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力(li)即克服彈簧阻力(li)，使(shi)閥體的(de)(de)推桿移(yi)動(dong)，將閥門(men)(men)開(kai)啟;當(dang)(dang)勵磁(ci)(ci)(ci)繞(rao)組(zu)斷電(dian)(dian)(dian)后，在復(fu)位彈簧作用下，閥體推桿便(bian)推動(dong)銜鐵(tie)(tie)，使(shi)其移(yi)動(dong)額定行程處，閥門(men)(men)關閉(bi)。閥用電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分(fen)為濕式和干(gan)式兩種(zhong)。濕式閥用電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)銜鐵(tie)(tie)在液(ye)壓油(you)中(zhong)工作，由(you)于(yu)油(you)的(de)(de)冷(leng)卻作用，使(shi)其與具有相同吸(xi)力(li)的(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相比，有較小(xiao)的(de)(de)尺寸。

電磁鐵的應用

門(men)(men)禁(jin)：為什么門(men)(men)禁(jin)可(ke)(ke)以(yi)(yi)在(zai)沒刷卡時把門(men)(men)牢(lao)牢(lao)的“抓住”？原來單元(yuan)門(men)(men)是由鋼材料做成的，那個(ge)(ge)金(jin)(jin)(jin)屬體(ti)在(zai)通(tong)電(dian)時可(ke)(ke)以(yi)(yi)產(chan)生強大的磁場(chang)，產(chan)生的磁力能把門(men)(men)牢(lao)牢(lao)的吸住，而刷卡的瞬間，切(qie)斷電(dian)流，金(jin)(jin)(jin)屬體(ti)失去磁性，我(wo)們就可(ke)(ke)以(yi)(yi)打開門(men)(men)了。那個(ge)(ge)金(jin)(jin)(jin)屬體(ti)其(qi)實(shi)是一(yi)塊電(dian)磁鐵。

電(dian)磁起(qi)(qi)重機(ji)：最直(zhi)接的(de)(de)應用之一(yi)是(shi)電(dian)磁起(qi)(qi)重機(ji)。電(dian)磁鐵安裝在吊車上(shang)，通(tong)電(dian)后(hou)吸起(qi)(qi)大(da)量鋼鐵，移動到另一(yi)個位置后(hou)切斷電(dian)流，鋼鐵被(bei)放下，免去了(le)打捆(kun)的(de)(de)麻煩。大(da)型電(dian)磁起(qi)(qi)重機(ji)一(yi)次可以吊起(qi)(qi)幾噸鋼材。

在(zai)電(dian)動機、發(fa)電(dian)機、電(dian)鈴(ling)和(he)電(dian)磁繼電(dian)器里也用(yong)到電(dian)磁鐵。全自動洗衣機的進水、排水閥(fa)門(men)，衛生間里感應式(shi)沖水器的閥(fa)門(men)，也都是由電(dian)磁鐵控制的。

電(dian)磁鐵的(de)另一個應用(yong)是產生(sheng)強(qiang)(qiang)磁場。現代(dai)技術中很多地方需(xu)要的(de)強(qiang)(qiang)磁場都由電(dian)磁鐵提供，如大型電(dian)動機、發(fa)電(dian)機、磁療設(she)備等。