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。這實際上是重慶電磁鐵原理的(de)最初發現。1823年(nian)，斯特(te)金也做了一(yi)次(ci)類(lei)似的(de)實驗(yan)：他在一(yi)根并非是磁(ci)(ci)鐵棒(bang)的(de)U型鐵棒(bang)上繞(rao)了18圈銅(tong)裸線(xian)，當(dang)銅(tong)線(xian)與伏打電池接通時，繞(rao)在U型鐵棒(bang)上的(de)銅(tong)線(xian)圈即產(chan)生(sheng)了密(mi)集(ji)的(de)磁(ci)(ci)場，這樣(yang)就使U型鐵棒(bang)變成(cheng)了一(yi)塊“電磁(ci)(ci)鐵”。這種電磁(ci)(ci)鐵上的(de)磁(ci)(ci)能(neng)(neng)要比永(yong)磁(ci)(ci)能(neng)(neng)大放(fang)多倍，它能(neng)(neng)吸起比它重(zhong)20倍的(de)鐵塊，而當(dang)電源切斷后，U型鐵棒(bang)就什么鐵塊也吸不(bu)住，重(zhong)新(xin)成(cheng)為(wei)一(yi)根普(pu)通的(de)鐵棒(bang)。

斯特金的電磁鐵發明(ming)，使人們看到了把電能(neng)轉化為磁能(neng)的光(guang)明(ming)前景，這(zhe)一發明(ming)很快在英國(guo)、美國(guo)以及西歐一些沿海國(guo)家傳播開(kai)來。

1829年(nian)，美國電學家(jia)亨利(li)對斯特金電磁鐵(tie)(tie)裝置進行了(le)一些革新，絕(jue)緣導線代替裸銅導線，因此(ci)不(bu)必擔心被銅導線過分靠近而短路。由于(yu)導線有了(le)絕(jue)緣層，就(jiu)可以將它們一圈(quan)(quan)圈(quan)(quan)地(di)緊緊地(di)繞在一起(qi)，由于(yu)線圈(quan)(quan)越密集，產生(sheng)的(de)磁場就(jiu)越強，這樣(yang)就(jiu)大(da)(da)大(da)(da)提高了(le)把電能(neng)(neng)轉化為磁能(neng)(neng)的(de)能(neng)(neng)力。到了(le)1831年(nian)，亨利(li)試(shi)制出(chu)了(le)一塊更(geng)新的(de)電磁鐵(tie)(tie)，雖(sui)然它的(de)體積并不(bu)大(da)(da)，但它能(neng)(neng)吸起(qi)1噸(dun)重的(de)鐵(tie)(tie)塊。

電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)內(nei)部(bu)帶有(you)(you)(you)鐵(tie)(tie)(tie)(tie)(tie)心(xin)的(de)(de)(de)(de)、利用通(tong)有(you)(you)(you)電流(liu)的(de)(de)(de)(de)線(xian)圈使其(qi)像(xiang)磁(ci)鐵(tie)(tie)(tie)(tie)(tie)一(yi)樣具有(you)(you)(you)磁(ci)性的(de)(de)(de)(de)裝置叫做電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)，通(tong)常制成條形或(huo)(huo)蹄(ti)形。鐵(tie)(tie)(tie)(tie)(tie)心(xin)要(yao)用容易(yi)磁(ci)化(hua)，又(you)容易(yi)消失(shi)磁(ci)性的(de)(de)(de)(de)軟鐵(tie)(tie)(tie)(tie)(tie)或(huo)(huo)硅鋼來(lai)制做。這樣的(de)(de)(de)(de)電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)在通(tong)電時有(you)(you)(you)磁(ci)性，斷電后就隨之(zhi)消失(shi)。 電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)有(you)(you)(you)許(xu)多優點：電磁(ci)鐵(tie)(tie)(tie)(tie)(tie)磁(ci)性的(de)(de)(de)(de)有(you)(you)(you)無(wu)，可以(yi)(yi)用通(tong)、斷電流(liu)控制。磁(ci)性的(de)(de)(de)(de)大小可以(yi)(yi)用電流(liu)的(de)(de)(de)(de)強(qiang)弱或(huo)(huo)線(xian)圈的(de)(de)(de)(de)匝數(shu)來(lai)控制。

電磁鐵的主要特點

1、采用(yong)全密封結構，防潮性能好。

2、經計算機優(you)化設計，結(jie)構合理、自(zi)重輕、吸力大、能耗低。

3、勵磁線圈(quan)經特別工(gong)藝處理，提高了線圈(quan)的(de)電器和機械性能(neng)，絕緣資(zi)料熱等級(ji)到達(da)C級(ji)，運(yun)用壽(shou)命長。

4、普通型電磁鐵(tie)的額定通電持續率由(you)曩(nang)昔的50%提(ti)(ti)高到60%，提(ti)(ti)高了電磁鐵(tie)的運用功率。

5、超高溫型電(dian)(dian)磁鐵采用獨特隔熱方式，其間(jian)被(bei)吸物溫度有曩昔(xi)的600℃提(ti)高700℃，擴大了電(dian)(dian)磁鐵的適用范圍。

6、裝置、運轉(zhuan)、保護簡潔。

電磁鐵工作原理

將電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)能變換為機械能以(yi)實(shi)現吸(xi)合作功的(de)(de)(de)(de)一種(zhong)電(dian)(dian)(dian)(dian)(dian)器。通(tong)常(chang)(chang)由軟磁(ci)(ci)(ci)(ci)材(cai)料制(zhi)成的(de)(de)(de)(de)鐵(tie)心(xin)、銜鐵(tie)和(he)勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)組(zu)成。當勵磁(ci)(ci)(ci)(ci)繞(rao)組(zu)通(tong)電(dian)(dian)(dian)(dian)(dian)時，繞(rao)組(zu)周圍產(chan)(chan)生磁(ci)(ci)(ci)(ci)場，鐵(tie)心(xin)磁(ci)(ci)(ci)(ci)化，并產(chan)(chan)生電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力吸(xi)引銜鐵(tie)，使之運(yun)動(dong)(dong)(dong)作功。電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)主要用于操動(dong)(dong)(dong)、牽引機械裝(zhuang)置，以(yi)達到預期的(de)(de)(de)(de)目的(de)(de)(de)(de)。工業上(shang)常(chang)(chang)用的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)有(you)制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)、牽引電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)、起重電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)和(he)閥(fa)用電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)等。此(ci)外，屬于電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)類的(de)(de)(de)(de)還有(you)用以(yi)傳遞或隔斷兩軸間的(de)(de)(de)(de)機械聯(lian)(lian)系的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)聯(lian)(lian)軸器;用在機床工作臺上(shang)以(yi)吸(xi)牢(lao)磁(ci)(ci)(ci)(ci)性(xing)材(cai)料工件的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)盤;供高能物理、核聚變研究、磁(ci)(ci)(ci)(ci)流體發電(dian)(dian)(dian)(dian)(dian)和(he)高速懸(xuan)浮列車等方面使用的(de)(de)(de)(de)、能產(chan)(chan)生高達數十特（斯拉）的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)通(tong)密度而幾乎(hu)不消(xiao)耗(hao)繞(rao)組(zu)功率的(de)(de)(de)(de)超導電(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)等。

起重電磁鐵

用來吊運和裝卸鐵(tie)(tie)磁(ci)性(xing)物(wu)體的(de)電磁(ci)鐵(tie)(tie)。工業上常用以吊運或裝卸鐵(tie)(tie)礦(kuang)石、鐵(tie)(tie)砂、廢(fei)鋼鐵(tie)(tie)、鋼錠(ding)、鋼軌(gui)以及各種鋼材(cai)和鋼質工件。起重電磁(ci)鐵(tie)(tie)通常做(zuo)成(cheng)圓盤形或矩形，并(bing)(bing)帶有內磁(ci)極(ji)和外磁(ci)極(ji)。當(dang)(dang)勵(li)磁(ci)繞(rao)(rao)組通電后，內外磁(ci)極(ji)均被(bei)磁(ci)化，吸引(yin)鋼質材(cai)料或工件（相當(dang)(dang)于(yu)一般電磁(ci)鐵(tie)(tie)中的(de)銜鐵(tie)(tie)），形成(cheng)一個(ge)閉合(he)的(de)磁(ci)路(lu)。為保護勵(li)磁(ci)繞(rao)(rao)組，使之不因磁(ci)極(ji)與被(bei)吸引(yin)物(wu)體間的(de)機械撞擊所損傷(shang)，起重電磁(ci)鐵(tie)(tie)通常采用甲殼式(shi)結(jie)構，并(bing)(bing)且采用直流勵(li)磁(ci)。

牽引電磁鐵

供牽(qian)(qian)引(yin)和推斥機械裝(zhuang)(zhuang)置用(yong)(yong)的(de)(de)(de)(de)一(yi)種電磁(ci)(ci)(ci)鐵(tie)(tie)。主要(yao)用(yong)(yong)于(yu)各(ge)種自動(dong)設備(bei)中(zhong)，以實現(xian)遠距離控制(zhi)。為(wei)(wei)了能夠在長行程(cheng)下(xia)獲得(de)較大的(de)(de)(de)(de)電磁(ci)(ci)(ci)吸(xi)力，牽(qian)(qian)引(yin)電磁(ci)(ci)(ci)鐵(tie)(tie)一(yi)般采用(yong)(yong)吸(xi)引(yin)特性比較平坦的(de)(de)(de)(de)甲(jia)殼式(shi)(shi)結構。其(qi)內部(bu)裝(zhuang)(zhuang)有鐵(tie)(tie)心、銜(xian)鐵(tie)(tie)和勵磁(ci)(ci)(ci)線(xian)圈。使用(yong)(yong)時，將鐵(tie)(tie)心固定在機械裝(zhuang)(zhuang)置的(de)(de)(de)(de)靜止(zhi)部(bu)件上(shang)，銜(xian)鐵(tie)(tie)則連接在牽(qian)(qian)引(yin)桿上(shang)。當(dang)勵磁(ci)(ci)(ci)繞組通電后(hou)，鐵(tie)(tie)心被(bei)磁(ci)(ci)(ci)化，產生電磁(ci)(ci)(ci)吸(xi)力吸(xi)引(yin)銜(xian)鐵(tie)(tie)，后(hou)者則通過(guo)牽(qian)(qian)引(yin)桿來操縱所控制(zhi)的(de)(de)(de)(de)機械裝(zhuang)(zhuang)置的(de)(de)(de)(de)機構。為(wei)(wei)了適(shi)應不同(tong)控制(zhi)對(dui)象的(de)(de)(de)(de)需要(yao)，牽(qian)(qian)引(yin)電磁(ci)(ci)(ci)鐵(tie)(tie)有拉動(dong)式(shi)(shi)和推動(dong)式(shi)(shi)兩種，但(dan)都(dou)不具備(bei)復(fu)位裝(zhuang)(zhuang)置。牽(qian)(qian)引(yin)電磁(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)(de)(de)主要(yao)技術指標為(wei)(wei)一(yi)定行程(cheng)下(xia)的(de)(de)(de)(de)電磁(ci)(ci)(ci)吸(xi)力、操作(zuo)頻率和壽命。

制動電磁鐵

作機(ji)械(xie)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)用(yong)(yong)的一種電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。主(zhu)要(yao)(yao)用(yong)(yong)于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)力(li)驅動(dong)(dong)(dong)(dong)(dong)(dong)(dong)裝(zhuang)置和起重運輸設備中，并與制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)配合(he)使(shi)用(yong)(yong)，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)機(ji)準確停車(che)和懸吊著的重物不致(zhi)墜落(luo)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)按(an)銜鐵(tie)(tie)(tie)行(xing)程(cheng)分為長行(xing)程(cheng)和短(duan)行(xing)程(cheng)兩(liang)類(lei);按(an)勵磁(ci)(ci)方(fang)式(shi)分為直流(liu)(liu)和交流(liu)(liu)、并勵和串(chuan)勵以及單相和三相等種類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的工作原理是(shi)：當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的繞(rao)組通電(dian)(dian)(dian)(dian)(dian)(dian)后(hou)，銜鐵(tie)(tie)(tie)被(bei)吸向鐵(tie)(tie)(tie)心，并通過(guo)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)中的停檔壓迫(po)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿，使(shi)之移動(dong)(dong)(dong)(dong)(dong)(dong)(dong)，從而迫(po)使(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)松閘。切斷(duan)線圈(quan)電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)后(hou)，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)桿在(zai)彈簧作用(yong)(yong)下使(shi)銜鐵(tie)(tie)(tie)脫離磁(ci)(ci)軛，而制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)則將機(ji)構剎住(zhu)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的主(zhu)要(yao)(yao)技術參(can)數是(shi)行(xing)程(cheng)、一定行(xing)程(cheng)下的電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)吸力(li)、操(cao)(cao)作頻(pin)率(lv)和通電(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率(lv)。操(cao)(cao)作頻(pin)率(lv)是(shi)指(zhi)每(mei)小時操(cao)(cao)作的次(ci)數;通電(dian)(dian)(dian)(dian)(dian)(dian)持(chi)續(xu)率(lv)是(shi)指(zhi)每(mei)次(ci)通電(dian)(dian)(dian)(dian)(dian)(dian)時間與每(mei)次(ci)通電(dian)(dian)(dian)(dian)(dian)(dian)及不通電(dian)(dian)(dian)(dian)(dian)(dian)時間之和的百(bai)分比。使(shi)用(yong)(yong)中，制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)與瓦式(shi)制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)相配合(he)時用(yong)(yong)短(duan)行(xing)程(cheng)類(lei);與皮帶制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)器(qi)相配合(he)時用(yong)(yong)長行(xing)程(cheng)類(lei)。制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)通過(guo)液壓方(fang)式(shi)將電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)力(li)傳遞給制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)機(ji)構的稱(cheng)液壓制(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)(dong)(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。

閥用電磁鐵

供遠距離操作(zuo)各種(zhong)液(ye)壓(ya)、氣(qi)動(dong)系統閥(fa)(fa)(fa)門(men)的(de)(de)(de)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)。常(chang)用(yong)(yong)于(yu)各種(zhong)金屬切(qie)削機床中。閥(fa)(fa)(fa)用(yong)(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)不設復(fu)(fu)位裝置，而由(you)閥(fa)(fa)(fa)體(ti)(ti)中的(de)(de)(de)彈簧(huang)使(shi)(shi)之復(fu)(fu)位。當電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)(de)勵(li)磁(ci)(ci)繞(rao)組(zu)通過電(dian)流(liu)時(shi)，電(dian)磁(ci)(ci)吸力(li)(li)即克服彈簧(huang)阻(zu)力(li)(li)，使(shi)(shi)閥(fa)(fa)(fa)體(ti)(ti)的(de)(de)(de)推桿(gan)移(yi)動(dong)，將(jiang)閥(fa)(fa)(fa)門(men)開啟;當勵(li)磁(ci)(ci)繞(rao)組(zu)斷電(dian)后，在(zai)復(fu)(fu)位彈簧(huang)作(zuo)用(yong)(yong)下，閥(fa)(fa)(fa)體(ti)(ti)推桿(gan)便推動(dong)銜鐵(tie)(tie)(tie)，使(shi)(shi)其移(yi)動(dong)額定行程(cheng)處，閥(fa)(fa)(fa)門(men)關(guan)閉。閥(fa)(fa)(fa)用(yong)(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)分為濕式和干式兩(liang)種(zhong)。濕式閥(fa)(fa)(fa)用(yong)(yong)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)的(de)(de)(de)銜鐵(tie)(tie)(tie)在(zai)液(ye)壓(ya)油(you)中工作(zuo)，由(you)于(yu)油(you)的(de)(de)(de)冷卻作(zuo)用(yong)(yong)，使(shi)(shi)其與具(ju)有相(xiang)同(tong)吸力(li)(li)的(de)(de)(de)電(dian)磁(ci)(ci)鐵(tie)(tie)(tie)相(xiang)比，有較小的(de)(de)(de)尺寸(cun)。

電磁鐵的應用

門(men)(men)禁：為什么門(men)(men)禁可(ke)以在沒(mei)刷卡時把(ba)門(men)(men)牢(lao)牢(lao)的“抓住”？原來單元門(men)(men)是由鋼材料做成的，那(nei)個金(jin)屬(shu)體(ti)在通電時可(ke)以產生強大的磁場，產生的磁力能(neng)把(ba)門(men)(men)牢(lao)牢(lao)的吸住，而刷卡的瞬間，切(qie)斷電流，金(jin)屬(shu)體(ti)失去(qu)磁性，我(wo)們就(jiu)可(ke)以打開門(men)(men)了(le)。那(nei)個金(jin)屬(shu)體(ti)其實(shi)是一塊電磁鐵(tie)。

電(dian)(dian)磁起(qi)(qi)重(zhong)機：最直接的應用(yong)之一(yi)(yi)是(shi)電(dian)(dian)磁起(qi)(qi)重(zhong)機。電(dian)(dian)磁鐵(tie)安裝在吊(diao)車上，通電(dian)(dian)后吸起(qi)(qi)大量(liang)鋼(gang)鐵(tie)，移(yi)動到另(ling)一(yi)(yi)個(ge)位置后切斷電(dian)(dian)流，鋼(gang)鐵(tie)被(bei)放下，免去了打捆的麻煩。大型電(dian)(dian)磁起(qi)(qi)重(zhong)機一(yi)(yi)次可(ke)以吊(diao)起(qi)(qi)幾噸鋼(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)器里也用(yong)到電(dian)磁(ci)鐵。全自動洗衣機(ji)(ji)的進水(shui)、排水(shui)閥門，衛生(sheng)間里感應式(shi)沖水(shui)器的閥門，也都是由電(dian)磁(ci)鐵控制(zhi)的。

電(dian)(dian)磁(ci)鐵(tie)的(de)另(ling)一個應用(yong)是產生(sheng)強磁(ci)場。現(xian)代(dai)技術中很多地方需(xu)要的(de)強磁(ci)場都由電(dian)(dian)磁(ci)鐵(tie)提供，如大型電(dian)(dian)動機(ji)、發電(dian)(dian)機(ji)、磁(ci)療設(she)備等。