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。這實際上是汕尾電磁鐵原理的(de)最初發(fa)現。1823年(nian)，斯(si)特(te)金也(ye)做了(le)(le)一次類似的(de)實(shi)驗：他在(zai)一根(gen)并非(fei)是(shi)磁(ci)(ci)鐵(tie)棒(bang)(bang)的(de)U型鐵(tie)棒(bang)(bang)上繞了(le)(le)18圈銅(tong)裸線(xian)，當(dang)銅(tong)線(xian)與伏打(da)電池接通時，繞在(zai)U型鐵(tie)棒(bang)(bang)上的(de)銅(tong)線(xian)圈即產生了(le)(le)密集的(de)磁(ci)(ci)場(chang)，這樣(yang)就使U型鐵(tie)棒(bang)(bang)變(bian)成了(le)(le)一塊“電磁(ci)(ci)鐵(tie)”。這種電磁(ci)(ci)鐵(tie)上的(de)磁(ci)(ci)能(neng)要比(bi)永(yong)磁(ci)(ci)能(neng)大(da)放多倍，它能(neng)吸起比(bi)它重20倍的(de)鐵(tie)塊，而當(dang)電源切斷后(hou)，U型鐵(tie)棒(bang)(bang)就什(shen)么(me)鐵(tie)塊也(ye)吸不(bu)住，重新成為一根(gen)普通的(de)鐵(tie)棒(bang)(bang)。

斯特金的(de)電磁鐵發明，使人們(men)看到(dao)了把電能轉化為磁能的(de)光明前景，這一(yi)發明很快在英國、美國以及西歐一(yi)些沿(yan)海(hai)國家傳播開來。

1829年(nian)(nian)，美國電學家亨利對斯特金(jin)電磁(ci)(ci)鐵(tie)(tie)裝置進行了一些革新(xin)(xin)，絕緣導線代替裸銅(tong)導線，因此不必擔心被銅(tong)導線過分靠近而短路。由于導線有了絕緣層，就可以將它們一圈圈地(di)緊(jin)緊(jin)地(di)繞(rao)在一起，由于線圈越(yue)密集，產(chan)生(sheng)的磁(ci)(ci)場(chang)就越(yue)強，這樣(yang)就大大提高了把電能轉化為磁(ci)(ci)能的能力。到了1831年(nian)(nian)，亨利試制出了一塊更新(xin)(xin)的電磁(ci)(ci)鐵(tie)(tie)，雖然它的體積(ji)并不大，但(dan)它能吸起1噸重的鐵(tie)(tie)塊。

電(dian)磁(ci)(ci)(ci)鐵(tie)內部帶有(you)(you)鐵(tie)心的、利用通有(you)(you)電(dian)流(liu)的線圈使(shi)其像磁(ci)(ci)(ci)鐵(tie)一樣(yang)具有(you)(you)磁(ci)(ci)(ci)性(xing)(xing)的裝置(zhi)叫(jiao)做(zuo)電(dian)磁(ci)(ci)(ci)鐵(tie)，通常制(zhi)成條形或蹄形。鐵(tie)心要用容易磁(ci)(ci)(ci)化，又容易消失磁(ci)(ci)(ci)性(xing)(xing)的軟鐵(tie)或硅鋼(gang)來制(zhi)做(zuo)。這樣(yang)的電(dian)磁(ci)(ci)(ci)鐵(tie)在通電(dian)時有(you)(you)磁(ci)(ci)(ci)性(xing)(xing)，斷(duan)電(dian)后(hou)就隨之消失。 電(dian)磁(ci)(ci)(ci)鐵(tie)有(you)(you)許多優點：電(dian)磁(ci)(ci)(ci)鐵(tie)磁(ci)(ci)(ci)性(xing)(xing)的有(you)(you)無，可以用通、斷(duan)電(dian)流(liu)控制(zhi)。磁(ci)(ci)(ci)性(xing)(xing)的大小(xiao)可以用電(dian)流(liu)的強弱或線圈的匝數來控制(zhi)。

電磁鐵的主要特點

1、采用全(quan)密封結構(gou)，防(fang)潮性能(neng)好。

2、經計算機優化設(she)計，結構(gou)合(he)理、自重輕、吸力大(da)、能耗低。

3、勵(li)磁線圈經特(te)別工(gong)藝處理(li)，提高了線圈的電器和機械性(xing)能，絕緣資(zi)料熱等級(ji)到達C級(ji)，運用壽命(ming)長。

4、普通型電磁鐵(tie)的額定通電持續率由曩昔的50%提高到(dao)60%，提高了電磁鐵(tie)的運(yun)用功率。

5、超(chao)高溫(wen)型電磁鐵采用獨特隔熱方式，其間被(bei)吸物(wu)溫(wen)度有曩昔(xi)的600℃提高700℃，擴大了電磁鐵的適用范圍。

6、裝置、運轉、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)能(neng)變換為(wei)機(ji)(ji)械能(neng)以(yi)(yi)(yi)實(shi)現吸(xi)合(he)作功的(de)(de)(de)一種電(dian)(dian)(dian)器。通常由軟磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)材料制(zhi)成的(de)(de)(de)鐵(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)和勵(li)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)繞組組成。當勵(li)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)繞組通電(dian)(dian)(dian)時，繞組周(zhou)圍產(chan)(chan)生(sheng)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)場，鐵(tie)(tie)(tie)心磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)化，并產(chan)(chan)生(sheng)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)力吸(xi)引銜(xian)鐵(tie)(tie)(tie)，使(shi)之運動(dong)作功。電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)主要(yao)用(yong)(yong)(yong)于操動(dong)、牽引機(ji)(ji)械裝置，以(yi)(yi)(yi)達到(dao)預期的(de)(de)(de)目的(de)(de)(de)。工(gong)(gong)業上(shang)常用(yong)(yong)(yong)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)有制(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、牽引電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)、起(qi)重(zhong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)和閥用(yong)(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。此外，屬于電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)類的(de)(de)(de)還有用(yong)(yong)(yong)以(yi)(yi)(yi)傳遞或隔(ge)斷兩軸間(jian)的(de)(de)(de)機(ji)(ji)械聯系(xi)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)聯軸器;用(yong)(yong)(yong)在機(ji)(ji)床工(gong)(gong)作臺上(shang)以(yi)(yi)(yi)吸(xi)牢磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)性材料工(gong)(gong)件(jian)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)吸(xi)盤;供(gong)高能(neng)物理、核聚變研究(jiu)、磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)流體發電(dian)(dian)(dian)和高速懸浮列(lie)車等(deng)方面使(shi)用(yong)(yong)(yong)的(de)(de)(de)、能(neng)產(chan)(chan)生(sheng)高達數十特（斯拉(la)）的(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)通密(mi)度而幾乎(hu)不消耗繞組功率的(de)(de)(de)超導電(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)(ci)(ci)(ci)鐵(tie)(tie)(tie)等(deng)。

起重電磁鐵

用來吊運和裝(zhuang)卸(xie)鐵(tie)(tie)磁(ci)(ci)性物(wu)體的電磁(ci)(ci)鐵(tie)(tie)。工業(ye)上常(chang)用以(yi)吊運或(huo)裝(zhuang)卸(xie)鐵(tie)(tie)礦(kuang)石、鐵(tie)(tie)砂(sha)、廢鋼鐵(tie)(tie)、鋼錠、鋼軌以(yi)及(ji)各種鋼材(cai)和鋼質工件(jian)。起重(zhong)(zhong)電磁(ci)(ci)鐵(tie)(tie)通(tong)常(chang)做成(cheng)圓盤(pan)形(xing)或(huo)矩(ju)形(xing)，并(bing)帶有內磁(ci)(ci)極(ji)和外磁(ci)(ci)極(ji)。當勵磁(ci)(ci)繞組(zu)通(tong)電后，內外磁(ci)(ci)極(ji)均被磁(ci)(ci)化，吸引鋼質材(cai)料或(huo)工件(jian)（相當于一般電磁(ci)(ci)鐵(tie)(tie)中的銜鐵(tie)(tie)），形(xing)成(cheng)一個閉合的磁(ci)(ci)路。為保護勵磁(ci)(ci)繞組(zu)，使之不因磁(ci)(ci)極(ji)與被吸引物(wu)體間(jian)的機械撞擊(ji)所損(sun)傷，起重(zhong)(zhong)電磁(ci)(ci)鐵(tie)(tie)通(tong)常(chang)采用甲(jia)殼式(shi)結構(gou)，并(bing)且采用直流(liu)勵磁(ci)(ci)。

牽引電磁鐵

供牽引(yin)(yin)(yin)和推斥(chi)機(ji)械裝(zhuang)(zhuang)(zhuang)置用(yong)(yong)的(de)(de)(de)一(yi)種(zhong)電(dian)磁(ci)(ci)(ci)鐵。主要(yao)(yao)用(yong)(yong)于各種(zhong)自(zi)動(dong)設備中，以實現遠距離控(kong)制(zhi)。為(wei)了能夠在(zai)長行程下獲得(de)較(jiao)大的(de)(de)(de)電(dian)磁(ci)(ci)(ci)吸力(li)(li)，牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)(ci)鐵一(yi)般采用(yong)(yong)吸引(yin)(yin)(yin)特性比(bi)較(jiao)平坦的(de)(de)(de)甲殼式(shi)結構。其內部(bu)裝(zhuang)(zhuang)(zhuang)有(you)(you)鐵心、銜鐵和勵磁(ci)(ci)(ci)線(xian)圈(quan)。使用(yong)(yong)時，將鐵心固定(ding)在(zai)機(ji)械裝(zhuang)(zhuang)(zhuang)置的(de)(de)(de)靜止(zhi)部(bu)件上(shang)，銜鐵則(ze)連接(jie)在(zai)牽引(yin)(yin)(yin)桿(gan)上(shang)。當勵磁(ci)(ci)(ci)繞組通(tong)電(dian)后，鐵心被(bei)磁(ci)(ci)(ci)化(hua)，產(chan)生電(dian)磁(ci)(ci)(ci)吸力(li)(li)吸引(yin)(yin)(yin)銜鐵，后者則(ze)通(tong)過牽引(yin)(yin)(yin)桿(gan)來操(cao)縱所控(kong)制(zhi)的(de)(de)(de)機(ji)械裝(zhuang)(zhuang)(zhuang)置的(de)(de)(de)機(ji)構。為(wei)了適(shi)應(ying)不同控(kong)制(zhi)對象(xiang)的(de)(de)(de)需要(yao)(yao)，牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)(ci)鐵有(you)(you)拉動(dong)式(shi)和推動(dong)式(shi)兩種(zhong)，但都(dou)不具備復(fu)位裝(zhuang)(zhuang)(zhuang)置。牽引(yin)(yin)(yin)電(dian)磁(ci)(ci)(ci)鐵的(de)(de)(de)主要(yao)(yao)技(ji)術指標為(wei)一(yi)定(ding)行程下的(de)(de)(de)電(dian)磁(ci)(ci)(ci)吸力(li)(li)、操(cao)作頻率(lv)和壽命。

制動電磁鐵

作(zuo)機(ji)械(xie)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)用(yong)(yong)的(de)一(yi)種電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。主要用(yong)(yong)于電(dian)(dian)(dian)(dian)力驅動(dong)(dong)(dong)(dong)(dong)裝置和(he)(he)起重(zhong)(zhong)運輸設備中(zhong)，并與(yu)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)配合使(shi)(shi)用(yong)(yong)，使(shi)(shi)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)準確(que)停(ting)車和(he)(he)懸吊著的(de)重(zhong)(zhong)物不(bu)致墜落(luo)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)按銜(xian)鐵(tie)行(xing)(xing)程(cheng)分為長行(xing)(xing)程(cheng)和(he)(he)短行(xing)(xing)程(cheng)兩類(lei)(lei)(lei);按勵(li)磁(ci)(ci)(ci)方式(shi)分為直流和(he)(he)交流、并勵(li)和(he)(he)串勵(li)以及(ji)單(dan)相和(he)(he)三相等種類(lei)(lei)(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)工作(zuo)原理是(shi)：當電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)繞組通(tong)電(dian)(dian)(dian)(dian)后，銜(xian)鐵(tie)被吸向(xiang)鐵(tie)心(xin)，并通(tong)過制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)中(zhong)的(de)停(ting)檔壓(ya)(ya)迫制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)，使(shi)(shi)之移動(dong)(dong)(dong)(dong)(dong)，從而迫使(shi)(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)松閘。切斷線圈電(dian)(dian)(dian)(dian)源后，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)桿(gan)在彈(dan)簧作(zuo)用(yong)(yong)下(xia)使(shi)(shi)銜(xian)鐵(tie)脫離磁(ci)(ci)(ci)軛，而制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)則將機(ji)構(gou)剎住。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)主要技(ji)術參數是(shi)行(xing)(xing)程(cheng)、一(yi)定行(xing)(xing)程(cheng)下(xia)的(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)吸力、操作(zuo)頻(pin)率(lv)和(he)(he)通(tong)電(dian)(dian)(dian)(dian)持續率(lv)。操作(zuo)頻(pin)率(lv)是(shi)指(zhi)每(mei)(mei)(mei)小時操作(zuo)的(de)次(ci)(ci)數;通(tong)電(dian)(dian)(dian)(dian)持續率(lv)是(shi)指(zhi)每(mei)(mei)(mei)次(ci)(ci)通(tong)電(dian)(dian)(dian)(dian)時間與(yu)每(mei)(mei)(mei)次(ci)(ci)通(tong)電(dian)(dian)(dian)(dian)及(ji)不(bu)通(tong)電(dian)(dian)(dian)(dian)時間之和(he)(he)的(de)百分比。使(shi)(shi)用(yong)(yong)中(zhong)，制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)與(yu)瓦(wa)式(shi)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時用(yong)(yong)短行(xing)(xing)程(cheng)類(lei)(lei)(lei);與(yu)皮帶制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)器(qi)(qi)相配合時用(yong)(yong)長行(xing)(xing)程(cheng)類(lei)(lei)(lei)。制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)過液(ye)壓(ya)(ya)方式(shi)將電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)力傳遞(di)給制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)機(ji)構(gou)的(de)稱液(ye)壓(ya)(ya)制(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。

閥用電磁鐵

供遠距離(li)操作(zuo)各(ge)種液壓(ya)、氣動(dong)系統閥(fa)(fa)門(men)的(de)(de)電(dian)磁鐵。常用(yong)(yong)(yong)(yong)于各(ge)種金屬切削機(ji)床(chuang)中(zhong)。閥(fa)(fa)用(yong)(yong)(yong)(yong)電(dian)磁鐵不(bu)設復位(wei)裝(zhuang)置，而由(you)閥(fa)(fa)體中(zhong)的(de)(de)彈簧(huang)使之復位(wei)。當電(dian)磁鐵的(de)(de)勵磁繞組通(tong)過電(dian)流時，電(dian)磁吸力即克服(fu)彈簧(huang)阻力，使閥(fa)(fa)體的(de)(de)推(tui)桿移動(dong)，將閥(fa)(fa)門(men)開啟;當勵磁繞組斷電(dian)后(hou)，在(zai)復位(wei)彈簧(huang)作(zuo)用(yong)(yong)(yong)(yong)下，閥(fa)(fa)體推(tui)桿便推(tui)動(dong)銜鐵，使其移動(dong)額定行程處，閥(fa)(fa)門(men)關閉。閥(fa)(fa)用(yong)(yong)(yong)(yong)電(dian)磁鐵分(fen)為濕式和(he)干式兩種。濕式閥(fa)(fa)用(yong)(yong)(yong)(yong)電(dian)磁鐵的(de)(de)銜鐵在(zai)液壓(ya)油中(zhong)工作(zuo)，由(you)于油的(de)(de)冷卻作(zuo)用(yong)(yong)(yong)(yong)，使其與具有(you)相同(tong)吸力的(de)(de)電(dian)磁鐵相比，有(you)較小的(de)(de)尺寸。

電磁鐵的應用

門(men)禁：為(wei)什么門(men)禁可(ke)以在沒刷卡時把(ba)(ba)門(men)牢牢的(de)(de)“抓住”？原(yuan)來單元門(men)是由鋼材料做(zuo)成的(de)(de)，那個金(jin)屬體(ti)在通電(dian)時可(ke)以產生強大的(de)(de)磁(ci)(ci)場，產生的(de)(de)磁(ci)(ci)力能把(ba)(ba)門(men)牢牢的(de)(de)吸住，而(er)刷卡的(de)(de)瞬間，切斷電(dian)流(liu)，金(jin)屬體(ti)失去磁(ci)(ci)性(xing)，我(wo)們就可(ke)以打(da)開門(men)了(le)。那個金(jin)屬體(ti)其實是一(yi)塊(kuai)電(dian)磁(ci)(ci)鐵。

電(dian)磁(ci)(ci)起重機：最直接的(de)應用之一(yi)是電(dian)磁(ci)(ci)起重機。電(dian)磁(ci)(ci)鐵(tie)安裝在吊車上，通電(dian)后吸起大量(liang)鋼(gang)鐵(tie)，移(yi)動到另(ling)一(yi)個位置后切斷(duan)電(dian)流，鋼(gang)鐵(tie)被放下，免去了打(da)捆的(de)麻煩。大型電(dian)磁(ci)(ci)起重機一(yi)次(ci)可以吊起幾噸鋼(gang)材。

在電(dian)(dian)動(dong)機(ji)(ji)、發電(dian)(dian)機(ji)(ji)、電(dian)(dian)鈴(ling)和(he)電(dian)(dian)磁繼(ji)電(dian)(dian)器里也用到電(dian)(dian)磁鐵(tie)。全自動(dong)洗衣(yi)機(ji)(ji)的(de)(de)(de)進(jin)水、排水閥門，衛生間(jian)里感應式沖水器的(de)(de)(de)閥門，也都是(shi)由電(dian)(dian)磁鐵(tie)控(kong)制(zhi)的(de)(de)(de)。

電磁(ci)(ci)鐵的另一(yi)個應(ying)用是(shi)產生強磁(ci)(ci)場。現代技術中很多地方需要的強磁(ci)(ci)場都由電磁(ci)(ci)鐵提供，如大型電動機、發(fa)電機、磁(ci)(ci)療設備(bei)等。