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。這實際上是合肥電磁鐵原(yuan)理的(de)最初發現。1823年，斯特金(jin)也做了(le)(le)一次類似(si)的(de)實驗：他在一根并非是磁(ci)(ci)(ci)鐵(tie)棒(bang)(bang)(bang)的(de)U型鐵(tie)棒(bang)(bang)(bang)上(shang)繞了(le)(le)18圈(quan)銅(tong)(tong)裸線，當銅(tong)(tong)線與伏(fu)打電池接通(tong)時，繞在U型鐵(tie)棒(bang)(bang)(bang)上(shang)的(de)銅(tong)(tong)線圈(quan)即產(chan)生了(le)(le)密(mi)集的(de)磁(ci)(ci)(ci)場，這樣就(jiu)使U型鐵(tie)棒(bang)(bang)(bang)變成了(le)(le)一塊“電磁(ci)(ci)(ci)鐵(tie)”。這種電磁(ci)(ci)(ci)鐵(tie)上(shang)的(de)磁(ci)(ci)(ci)能(neng)要比永磁(ci)(ci)(ci)能(neng)大(da)放(fang)多倍(bei)，它能(neng)吸(xi)起比它重20倍(bei)的(de)鐵(tie)塊，而當電源切斷后，U型鐵(tie)棒(bang)(bang)(bang)就(jiu)什(shen)么(me)鐵(tie)塊也吸(xi)不住，重新成為一根普通(tong)的(de)鐵(tie)棒(bang)(bang)(bang)。

斯特金的電磁鐵發明(ming)(ming)，使人們(men)看到了把(ba)電能(neng)(neng)轉(zhuan)化為磁能(neng)(neng)的光明(ming)(ming)前景，這一發明(ming)(ming)很快在英國(guo)(guo)、美國(guo)(guo)以及(ji)西歐一些沿海國(guo)(guo)家(jia)傳(chuan)播(bo)開來(lai)。

1829年，美(mei)國電學家亨(heng)利(li)對斯特金(jin)電磁(ci)(ci)鐵裝置進(jin)行了(le)一(yi)些革新，絕緣(yuan)(yuan)導(dao)(dao)線代替(ti)裸(luo)銅導(dao)(dao)線，因此不(bu)必擔心被銅導(dao)(dao)線過分靠近而短路。由于(yu)導(dao)(dao)線有了(le)絕緣(yuan)(yuan)層(ceng)，就可以將(jiang)它(ta)們一(yi)圈圈地緊緊地繞在一(yi)起，由于(yu)線圈越密集，產生的(de)磁(ci)(ci)場就越強(qiang)，這(zhe)樣就大(da)(da)大(da)(da)提(ti)高了(le)把電能轉(zhuan)化為磁(ci)(ci)能的(de)能力。到(dao)了(le)1831年，亨(heng)利(li)試制出了(le)一(yi)塊(kuai)更新的(de)電磁(ci)(ci)鐵，雖(sui)然(ran)它(ta)的(de)體積并(bing)不(bu)大(da)(da)，但它(ta)能吸起1噸重的(de)鐵塊(kuai)。

電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)內部帶有(you)(you)鐵(tie)(tie)(tie)心的(de)(de)、利用通有(you)(you)電(dian)流的(de)(de)線圈(quan)使其(qi)像磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)一樣具有(you)(you)磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)裝置(zhi)叫做電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)，通常制(zhi)(zhi)(zhi)成條(tiao)形或(huo)蹄形。鐵(tie)(tie)(tie)心要用容(rong)易磁(ci)(ci)(ci)(ci)(ci)化，又容(rong)易消失磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)軟鐵(tie)(tie)(tie)或(huo)硅鋼(gang)來制(zhi)(zhi)(zhi)做。這(zhe)樣的(de)(de)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)在通電(dian)時有(you)(you)磁(ci)(ci)(ci)(ci)(ci)性(xing)，斷電(dian)后就隨之消失。 電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)有(you)(you)許多優點：電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)有(you)(you)無，可以用通、斷電(dian)流控(kong)(kong)制(zhi)(zhi)(zhi)。磁(ci)(ci)(ci)(ci)(ci)性(xing)的(de)(de)大小可以用電(dian)流的(de)(de)強弱或(huo)線圈(quan)的(de)(de)匝數(shu)來控(kong)(kong)制(zhi)(zhi)(zhi)。

電磁鐵的主要特點

1、采用全密封結構，防(fang)潮性能好。

2、經計算機優(you)化(hua)設計，結構合(he)理、自重(zhong)輕、吸力大、能耗低。

3、勵磁(ci)線圈經特(te)別工(gong)藝(yi)處理，提高了線圈的電器和機械性能，絕(jue)緣資(zi)料熱等級(ji)到達C級(ji)，運用壽命長。

4、普(pu)通(tong)型電磁(ci)鐵的額定通(tong)電持(chi)續(xu)率(lv)由(you)曩昔(xi)的50%提(ti)高到60%，提(ti)高了電磁(ci)鐵的運用功率(lv)。

5、超高(gao)溫型電磁鐵采用獨(du)特隔熱方(fang)式，其間被吸物(wu)溫度(du)有(you)曩昔的600℃提(ti)高(gao)700℃，擴大了(le)電磁鐵的適用范圍(wei)。

6、裝置(zhi)、運轉(zhuan)、保護簡潔(jie)。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)能(neng)變換為機械能(neng)以實現吸(xi)(xi)合作功的(de)一(yi)種電(dian)(dian)(dian)(dian)(dian)器(qi)。通常由(you)軟磁(ci)(ci)(ci)材料(liao)制成的(de)鐵(tie)心(xin)、銜鐵(tie)和勵磁(ci)(ci)(ci)繞(rao)(rao)組組成。當(dang)勵磁(ci)(ci)(ci)繞(rao)(rao)組通電(dian)(dian)(dian)(dian)(dian)時，繞(rao)(rao)組周(zhou)圍(wei)產(chan)(chan)生(sheng)磁(ci)(ci)(ci)場，鐵(tie)心(xin)磁(ci)(ci)(ci)化，并產(chan)(chan)生(sheng)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)力吸(xi)(xi)引(yin)銜鐵(tie)，使之運動(dong)作功。電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)主要(yao)用(yong)(yong)于操動(dong)、牽引(yin)機械裝置，以達(da)到預期的(de)目的(de)。工(gong)業上常用(yong)(yong)的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)有(you)制動(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)、牽引(yin)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)和閥用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)等。此外，屬于電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)類的(de)還有(you)用(yong)(yong)以傳遞或隔斷兩(liang)軸間的(de)機械聯(lian)系的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)聯(lian)軸器(qi);用(yong)(yong)在機床工(gong)作臺上以吸(xi)(xi)牢磁(ci)(ci)(ci)性材料(liao)工(gong)件的(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)(xi)盤(pan);供高(gao)能(neng)物理(li)、核(he)聚變研(yan)究、磁(ci)(ci)(ci)流體(ti)發電(dian)(dian)(dian)(dian)(dian)和高(gao)速懸(xuan)浮列車等方面使用(yong)(yong)的(de)、能(neng)產(chan)(chan)生(sheng)高(gao)達(da)數十特（斯拉(la)）的(de)磁(ci)(ci)(ci)通密度而幾乎不消耗繞(rao)(rao)組功率的(de)超(chao)導(dao)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)等。

起重電磁鐵

用來吊運和(he)(he)裝卸鐵(tie)(tie)(tie)磁(ci)(ci)性物體的電磁(ci)(ci)鐵(tie)(tie)(tie)。工(gong)業上常用以吊運或(huo)裝卸鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂、廢(fei)鋼(gang)鐵(tie)(tie)(tie)、鋼(gang)錠、鋼(gang)軌以及各種鋼(gang)材(cai)和(he)(he)鋼(gang)質(zhi)工(gong)件(jian)。起(qi)重(zhong)(zhong)電磁(ci)(ci)鐵(tie)(tie)(tie)通常做(zuo)成圓(yuan)盤形(xing)或(huo)矩形(xing)，并(bing)(bing)帶(dai)有(you)內磁(ci)(ci)極(ji)和(he)(he)外磁(ci)(ci)極(ji)。當勵(li)磁(ci)(ci)繞(rao)組通電后，內外磁(ci)(ci)極(ji)均被磁(ci)(ci)化，吸(xi)引(yin)鋼(gang)質(zhi)材(cai)料(liao)或(huo)工(gong)件(jian)（相(xiang)當于一(yi)般電磁(ci)(ci)鐵(tie)(tie)(tie)中的銜鐵(tie)(tie)(tie)），形(xing)成一(yi)個(ge)閉合的磁(ci)(ci)路(lu)。為保護勵(li)磁(ci)(ci)繞(rao)組，使之不因磁(ci)(ci)極(ji)與被吸(xi)引(yin)物體間的機械撞(zhuang)擊所損傷，起(qi)重(zhong)(zhong)電磁(ci)(ci)鐵(tie)(tie)(tie)通常采用甲殼式結構，并(bing)(bing)且采用直流勵(li)磁(ci)(ci)。

牽引電磁鐵

供牽引(yin)(yin)(yin)和(he)推(tui)斥機械(xie)裝(zhuang)置(zhi)(zhi)(zhi)用(yong)的(de)一(yi)種電(dian)磁(ci)鐵(tie)(tie)。主要用(yong)于各種自動設備中，以(yi)實現(xian)遠距離(li)控(kong)(kong)制(zhi)。為了能夠(gou)在長(chang)行(xing)程下獲得(de)較大的(de)電(dian)磁(ci)吸力，牽引(yin)(yin)(yin)電(dian)磁(ci)鐵(tie)(tie)一(yi)般采用(yong)吸引(yin)(yin)(yin)特性比較平坦的(de)甲(jia)殼式結(jie)構(gou)。其(qi)內(nei)部(bu)裝(zhuang)有鐵(tie)(tie)心(xin)、銜鐵(tie)(tie)和(he)勵(li)磁(ci)線圈。使用(yong)時，將鐵(tie)(tie)心(xin)固定在機械(xie)裝(zhuang)置(zhi)(zhi)(zhi)的(de)靜止(zhi)部(bu)件上(shang)，銜鐵(tie)(tie)則連接(jie)在牽引(yin)(yin)(yin)桿(gan)(gan)上(shang)。當勵(li)磁(ci)繞組通電(dian)后(hou)，鐵(tie)(tie)心(xin)被磁(ci)化，產生電(dian)磁(ci)吸力吸引(yin)(yin)(yin)銜鐵(tie)(tie)，后(hou)者則通過(guo)牽引(yin)(yin)(yin)桿(gan)(gan)來操縱所(suo)控(kong)(kong)制(zhi)的(de)機械(xie)裝(zhuang)置(zhi)(zhi)(zhi)的(de)機構(gou)。為了適應不同(tong)控(kong)(kong)制(zhi)對象的(de)需要，牽引(yin)(yin)(yin)電(dian)磁(ci)鐵(tie)(tie)有拉動式和(he)推(tui)動式兩種，但都不具備復(fu)位(wei)裝(zhuang)置(zhi)(zhi)(zhi)。牽引(yin)(yin)(yin)電(dian)磁(ci)鐵(tie)(tie)的(de)主要技術指標為一(yi)定行(xing)程下的(de)電(dian)磁(ci)吸力、操作頻率和(he)壽(shou)命。

制動電磁鐵

作機(ji)械制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)用(yong)(yong)(yong)的(de)(de)一(yi)種電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)。主要(yao)用(yong)(yong)(yong)于電(dian)(dian)(dian)(dian)力(li)驅動(dong)(dong)(dong)(dong)裝置和起重運輸設備中，并(bing)與制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)配合(he)使(shi)用(yong)(yong)(yong)，使(shi)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)機(ji)準(zhun)確(que)停(ting)車和懸(xuan)吊著(zhu)的(de)(de)重物不(bu)致墜(zhui)落。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)按(an)銜鐵(tie)(tie)(tie)(tie)(tie)行(xing)(xing)程(cheng)分(fen)為長行(xing)(xing)程(cheng)和短(duan)(duan)行(xing)(xing)程(cheng)兩類(lei);按(an)勵磁(ci)(ci)(ci)方式(shi)分(fen)為直流(liu)和交(jiao)流(liu)、并(bing)勵和串勵以及(ji)(ji)單相(xiang)(xiang)和三相(xiang)(xiang)等(deng)種類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)的(de)(de)工作原(yuan)理是(shi)：當(dang)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)的(de)(de)繞組(zu)通(tong)電(dian)(dian)(dian)(dian)后，銜鐵(tie)(tie)(tie)(tie)(tie)被(bei)吸(xi)向鐵(tie)(tie)(tie)(tie)(tie)心，并(bing)通(tong)過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)中的(de)(de)停(ting)檔壓(ya)迫(po)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)桿(gan)，使(shi)之移動(dong)(dong)(dong)(dong)，從而迫(po)使(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)松閘。切斷線圈電(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)桿(gan)在彈簧作用(yong)(yong)(yong)下使(shi)銜鐵(tie)(tie)(tie)(tie)(tie)脫離磁(ci)(ci)(ci)軛，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)則將機(ji)構剎住。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)的(de)(de)主要(yao)技術(shu)參數(shu)是(shi)行(xing)(xing)程(cheng)、一(yi)定行(xing)(xing)程(cheng)下的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力(li)、操(cao)(cao)作頻率和通(tong)電(dian)(dian)(dian)(dian)持續(xu)率。操(cao)(cao)作頻率是(shi)指每小時(shi)(shi)操(cao)(cao)作的(de)(de)次數(shu);通(tong)電(dian)(dian)(dian)(dian)持續(xu)率是(shi)指每次通(tong)電(dian)(dian)(dian)(dian)時(shi)(shi)間(jian)與每次通(tong)電(dian)(dian)(dian)(dian)及(ji)(ji)不(bu)通(tong)電(dian)(dian)(dian)(dian)時(shi)(shi)間(jian)之和的(de)(de)百分(fen)比。使(shi)用(yong)(yong)(yong)中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)與瓦式(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)相(xiang)(xiang)配合(he)時(shi)(shi)用(yong)(yong)(yong)短(duan)(duan)行(xing)(xing)程(cheng)類(lei);與皮(pi)帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)器(qi)(qi)(qi)相(xiang)(xiang)配合(he)時(shi)(shi)用(yong)(yong)(yong)長行(xing)(xing)程(cheng)類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)通(tong)過(guo)液(ye)壓(ya)方式(shi)將電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)力(li)傳遞給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)機(ji)構的(de)(de)稱液(ye)壓(ya)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)。

閥用電磁鐵

供遠距離操作(zuo)各(ge)種液壓(ya)、氣動系統閥(fa)(fa)門(men)的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)。常用于各(ge)種金屬切削機床中。閥(fa)(fa)用電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)不設復位(wei)裝置，而由閥(fa)(fa)體中的(de)彈(dan)簧使(shi)(shi)之復位(wei)。當(dang)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)勵磁(ci)(ci)(ci)繞(rao)組通過(guo)電(dian)(dian)流時，電(dian)(dian)磁(ci)(ci)(ci)吸(xi)力(li)即克服彈(dan)簧阻力(li)，使(shi)(shi)閥(fa)(fa)體的(de)推桿(gan)移動，將(jiang)閥(fa)(fa)門(men)開(kai)啟;當(dang)勵磁(ci)(ci)(ci)繞(rao)組斷電(dian)(dian)后，在復位(wei)彈(dan)簧作(zuo)用下，閥(fa)(fa)體推桿(gan)便推動銜(xian)鐵(tie)(tie)，使(shi)(shi)其移動額定行程(cheng)處(chu)，閥(fa)(fa)門(men)關(guan)閉(bi)。閥(fa)(fa)用電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)分為濕式和干(gan)式兩種。濕式閥(fa)(fa)用電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)的(de)銜(xian)鐵(tie)(tie)在液壓(ya)油中工作(zuo)，由于油的(de)冷卻作(zuo)用，使(shi)(shi)其與具(ju)有相(xiang)同吸(xi)力(li)的(de)電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)相(xiang)比(bi)，有較(jiao)小的(de)尺寸。

電磁鐵的應用

門(men)(men)禁：為(wei)什么門(men)(men)禁可以(yi)在沒(mei)刷(shua)卡時把門(men)(men)牢(lao)牢(lao)的(de)(de)“抓住”？原來單元門(men)(men)是(shi)由鋼材料做成的(de)(de)，那個金屬體在通電時可以(yi)產生強(qiang)大的(de)(de)磁(ci)(ci)場，產生的(de)(de)磁(ci)(ci)力能(neng)把門(men)(men)牢(lao)牢(lao)的(de)(de)吸住，而刷(shua)卡的(de)(de)瞬間(jian)，切斷電流，金屬體失去磁(ci)(ci)性，我們(men)就可以(yi)打開門(men)(men)了。那個金屬體其實是(shi)一塊(kuai)電磁(ci)(ci)鐵。

電(dian)磁起重機：最直接的應用(yong)之一(yi)是(shi)電(dian)磁起重機。電(dian)磁鐵(tie)安裝在吊車上，通電(dian)后吸起大(da)量鋼鐵(tie)，移動到另一(yi)個位置后切(qie)斷電(dian)流，鋼鐵(tie)被放下，免去(qu)了打捆的麻煩。大(da)型電(dian)磁起重機一(yi)次(ci)可(ke)以吊起幾(ji)噸鋼材。

在電(dian)動機(ji)、發電(dian)機(ji)、電(dian)鈴(ling)和電(dian)磁繼電(dian)器里(li)也(ye)用(yong)到電(dian)磁鐵(tie)(tie)。全自動洗衣機(ji)的(de)(de)進水、排水閥(fa)門，衛生(sheng)間(jian)里(li)感應式沖(chong)水器的(de)(de)閥(fa)門，也(ye)都是由電(dian)磁鐵(tie)(tie)控(kong)制的(de)(de)。

電磁(ci)(ci)鐵的(de)另一(yi)個(ge)應用是(shi)產(chan)生強磁(ci)(ci)場。現代(dai)技術(shu)中很多地方需(xu)要的(de)強磁(ci)(ci)場都(dou)由電磁(ci)(ci)鐵提供，如(ru)大(da)型電動機、發電機、磁(ci)(ci)療(liao)設備等(deng)。