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)(de)(de)最(zui)初發現。1823年，斯特金(jin)也(ye)做(zuo)了(le)(le)一(yi)次類似的(de)(de)(de)實驗：他在(zai)一(yi)根(gen)并非是磁(ci)(ci)(ci)鐵(tie)(tie)棒(bang)(bang)的(de)(de)(de)U型(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)繞(rao)了(le)(le)18圈(quan)銅裸線，當(dang)銅線與伏打電(dian)(dian)池接通(tong)(tong)時，繞(rao)在(zai)U型(xing)鐵(tie)(tie)棒(bang)(bang)上(shang)的(de)(de)(de)銅線圈(quan)即產(chan)生了(le)(le)密集的(de)(de)(de)磁(ci)(ci)(ci)場，這樣(yang)就(jiu)使U型(xing)鐵(tie)(tie)棒(bang)(bang)變成了(le)(le)一(yi)塊(kuai)“電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)”。這種電(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)上(shang)的(de)(de)(de)磁(ci)(ci)(ci)能要比永磁(ci)(ci)(ci)能大放多倍，它能吸起比它重(zhong)20倍的(de)(de)(de)鐵(tie)(tie)塊(kuai)，而(er)當(dang)電(dian)(dian)源切(qie)斷(duan)后，U型(xing)鐵(tie)(tie)棒(bang)(bang)就(jiu)什么鐵(tie)(tie)塊(kuai)也(ye)吸不住，重(zhong)新成為一(yi)根(gen)普(pu)通(tong)(tong)的(de)(de)(de)鐵(tie)(tie)棒(bang)(bang)。

斯特金(jin)的電磁(ci)鐵發(fa)明，使(shi)人(ren)們看到了把電能(neng)轉(zhuan)化為磁(ci)能(neng)的光(guang)明前景(jing)，這(zhe)一發(fa)明很快在(zai)英國(guo)、美國(guo)以及西歐一些(xie)沿海國(guo)家傳播開(kai)來(lai)。

1829年(nian)(nian)，美國電(dian)學家亨利對斯特金電(dian)磁(ci)鐵裝置進行了一些革新(xin)，絕緣導線(xian)代替(ti)裸銅(tong)導線(xian)，因此不必擔心被銅(tong)導線(xian)過(guo)分靠近而短路。由于導線(xian)有了絕緣層，就可(ke)以將它(ta)們一圈圈地緊緊地繞在一起，由于線(xian)圈越(yue)密(mi)集(ji)，產生的磁(ci)場就越(yue)強，這樣就大大提高了把(ba)電(dian)能轉化為磁(ci)能的能力。到了1831年(nian)(nian)，亨利試(shi)制出了一塊更新(xin)的電(dian)磁(ci)鐵，雖然(ran)它(ta)的體積(ji)并不大，但(dan)它(ta)能吸起1噸重的鐵塊。

電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)內部(bu)帶有鐵(tie)(tie)心的、利用(yong)通有電(dian)(dian)(dian)流(liu)的線圈使其像(xiang)磁(ci)(ci)鐵(tie)(tie)一樣(yang)具有磁(ci)(ci)性的裝置叫(jiao)做(zuo)電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)，通常制成條形(xing)或蹄形(xing)。鐵(tie)(tie)心要用(yong)容易磁(ci)(ci)化，又容易消失磁(ci)(ci)性的軟鐵(tie)(tie)或硅(gui)鋼來(lai)制做(zuo)。這樣(yang)的電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)在通電(dian)(dian)(dian)時有磁(ci)(ci)性，斷電(dian)(dian)(dian)后就隨之(zhi)消失。 電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)有許(xu)多優點：電(dian)(dian)(dian)磁(ci)(ci)鐵(tie)(tie)磁(ci)(ci)性的有無，可以用(yong)通、斷電(dian)(dian)(dian)流(liu)控制。磁(ci)(ci)性的大小可以用(yong)電(dian)(dian)(dian)流(liu)的強(qiang)弱或線圈的匝數(shu)來(lai)控制。

電磁鐵的主要特點

1、采用全(quan)密(mi)封結構，防潮(chao)性(xing)能好(hao)。

2、經(jing)計(ji)算機優化設計(ji)，結構合理、自重輕、吸力大、能耗低。

3、勵磁(ci)線圈經(jing)特(te)別(bie)工藝處(chu)理，提(ti)高(gao)了線圈的電器和機械性能，絕緣資料熱(re)等級到達(da)C級，運(yun)用壽(shou)命長。

4、普通型(xing)電(dian)磁(ci)鐵的(de)額定通電(dian)持(chi)續率由曩昔(xi)的(de)50%提高(gao)到60%，提高(gao)了電(dian)磁(ci)鐵的(de)運(yun)用功(gong)率。

5、超高溫型電磁(ci)鐵采(cai)用獨(du)特(te)隔熱方式，其間被吸物溫度有曩昔(xi)的600℃提高700℃，擴大了電磁(ci)鐵的適用范圍。

6、裝置、運(yun)轉、保護簡潔(jie)。

電磁鐵工作原理

將電(dian)(dian)(dian)磁(ci)(ci)(ci)能變(bian)換為機(ji)械能以實現吸(xi)合作功的(de)(de)(de)一種電(dian)(dian)(dian)器。通常(chang)由軟(ruan)磁(ci)(ci)(ci)材(cai)料制成(cheng)的(de)(de)(de)鐵(tie)(tie)(tie)(tie)(tie)(tie)心、銜(xian)鐵(tie)(tie)(tie)(tie)(tie)(tie)和勵(li)磁(ci)(ci)(ci)繞(rao)(rao)組(zu)(zu)組(zu)(zu)成(cheng)。當勵(li)磁(ci)(ci)(ci)繞(rao)(rao)組(zu)(zu)通電(dian)(dian)(dian)時(shi)，繞(rao)(rao)組(zu)(zu)周圍產(chan)生(sheng)磁(ci)(ci)(ci)場，鐵(tie)(tie)(tie)(tie)(tie)(tie)心磁(ci)(ci)(ci)化(hua)，并產(chan)生(sheng)電(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力吸(xi)引(yin)銜(xian)鐵(tie)(tie)(tie)(tie)(tie)(tie)，使(shi)之運動作功。電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)主要用(yong)(yong)于操動、牽引(yin)機(ji)械裝(zhuang)置(zhi)，以達(da)到預期的(de)(de)(de)目(mu)的(de)(de)(de)。工業上常(chang)用(yong)(yong)的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)有(you)制動電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)、牽引(yin)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)、起重電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)和閥用(yong)(yong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)等。此外，屬于電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)類(lei)的(de)(de)(de)還有(you)用(yong)(yong)以傳(chuan)遞或隔斷兩軸間的(de)(de)(de)機(ji)械聯(lian)系的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)聯(lian)軸器;用(yong)(yong)在機(ji)床工作臺上以吸(xi)牢(lao)磁(ci)(ci)(ci)性材(cai)料工件的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)盤(pan);供高能物理(li)、核聚(ju)變(bian)研(yan)究(jiu)、磁(ci)(ci)(ci)流(liu)體發電(dian)(dian)(dian)和高速(su)懸浮列車等方(fang)面使(shi)用(yong)(yong)的(de)(de)(de)、能產(chan)生(sheng)高達(da)數十特(te)（斯拉）的(de)(de)(de)磁(ci)(ci)(ci)通密度而幾乎不消耗繞(rao)(rao)組(zu)(zu)功率的(de)(de)(de)超(chao)導(dao)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)(tie)(tie)(tie)(tie)(tie)等。

起重電磁鐵

用來(lai)吊(diao)運和(he)裝卸(xie)鐵(tie)(tie)(tie)磁(ci)性物體的電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)。工業上常用以(yi)吊(diao)運或(huo)裝卸(xie)鐵(tie)(tie)(tie)礦石、鐵(tie)(tie)(tie)砂(sha)、廢鋼(gang)(gang)鐵(tie)(tie)(tie)、鋼(gang)(gang)錠、鋼(gang)(gang)軌以(yi)及各種鋼(gang)(gang)材和(he)鋼(gang)(gang)質工件(jian)。起重電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)通(tong)常做(zuo)成圓盤形或(huo)矩形，并(bing)(bing)帶有內(nei)磁(ci)極(ji)和(he)外(wai)磁(ci)極(ji)。當(dang)勵磁(ci)繞組通(tong)電(dian)(dian)后，內(nei)外(wai)磁(ci)極(ji)均被磁(ci)化，吸引鋼(gang)(gang)質材料或(huo)工件(jian)（相當(dang)于一般電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)中的銜鐵(tie)(tie)(tie)），形成一個(ge)閉合的磁(ci)路。為(wei)保(bao)護勵磁(ci)繞組，使之不因磁(ci)極(ji)與(yu)被吸引物體間的機(ji)械撞擊所(suo)損傷，起重電(dian)(dian)磁(ci)鐵(tie)(tie)(tie)通(tong)常采用甲殼(ke)式結構，并(bing)(bing)且采用直流勵磁(ci)。

牽引電磁鐵

供牽引(yin)(yin)和(he)(he)推斥機械(xie)裝置用(yong)(yong)(yong)的(de)(de)一(yi)種(zhong)(zhong)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)。主要用(yong)(yong)(yong)于各種(zhong)(zhong)自動設(she)備中，以實現遠距(ju)離控制。為(wei)了能夠在(zai)長行(xing)(xing)程下(xia)(xia)獲得較大的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力(li)，牽引(yin)(yin)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)一(yi)般(ban)采用(yong)(yong)(yong)吸(xi)引(yin)(yin)特(te)性比較平(ping)坦的(de)(de)甲殼式(shi)結構。其內(nei)部(bu)裝有鐵(tie)(tie)心、銜(xian)鐵(tie)(tie)和(he)(he)勵磁(ci)(ci)(ci)(ci)線圈。使用(yong)(yong)(yong)時，將鐵(tie)(tie)心固定(ding)(ding)在(zai)機械(xie)裝置的(de)(de)靜止(zhi)部(bu)件上，銜(xian)鐵(tie)(tie)則連接在(zai)牽引(yin)(yin)桿(gan)(gan)上。當勵磁(ci)(ci)(ci)(ci)繞組(zu)通電(dian)(dian)(dian)(dian)后，鐵(tie)(tie)心被磁(ci)(ci)(ci)(ci)化，產(chan)生電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力(li)吸(xi)引(yin)(yin)銜(xian)鐵(tie)(tie)，后者(zhe)則通過牽引(yin)(yin)桿(gan)(gan)來操縱所控制的(de)(de)機械(xie)裝置的(de)(de)機構。為(wei)了適(shi)應(ying)不同控制對象(xiang)的(de)(de)需要，牽引(yin)(yin)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)有拉動式(shi)和(he)(he)推動式(shi)兩種(zhong)(zhong)，但都不具備復位裝置。牽引(yin)(yin)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)鐵(tie)(tie)的(de)(de)主要技術指(zhi)標為(wei)一(yi)定(ding)(ding)行(xing)(xing)程下(xia)(xia)的(de)(de)電(dian)(dian)(dian)(dian)磁(ci)(ci)(ci)(ci)吸(xi)力(li)、操作頻率和(he)(he)壽命。

制動電磁鐵

作(zuo)(zuo)機械(xie)制(zhi)(zhi)(zhi)(zhi)動(dong)用(yong)的(de)(de)(de)一種(zhong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。主要(yao)用(yong)于電(dian)(dian)(dian)力(li)驅動(dong)裝置和(he)(he)起重運輸設備中，并與(yu)(yu)制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)配合使(shi)(shi)(shi)(shi)用(yong)，使(shi)(shi)(shi)(shi)電(dian)(dian)(dian)動(dong)機準確(que)停車和(he)(he)懸(xuan)吊著的(de)(de)(de)重物(wu)不致墜落。制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)按銜(xian)(xian)鐵(tie)行程分(fen)為長行程和(he)(he)短行程兩類;按勵(li)(li)磁(ci)(ci)(ci)方(fang)式分(fen)為直流和(he)(he)交(jiao)流、并勵(li)(li)和(he)(he)串勵(li)(li)以及單相(xiang)(xiang)和(he)(he)三相(xiang)(xiang)等種(zhong)類。制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)(de)(de)工作(zuo)(zuo)原(yuan)理是(shi)：當電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)(de)(de)繞組通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)后(hou)，銜(xian)(xian)鐵(tie)被吸(xi)向(xiang)鐵(tie)心(xin)，并通(tong)(tong)(tong)(tong)過制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)中的(de)(de)(de)停檔壓(ya)(ya)迫(po)制(zhi)(zhi)(zhi)(zhi)動(dong)桿，使(shi)(shi)(shi)(shi)之移動(dong)，從而(er)迫(po)使(shi)(shi)(shi)(shi)制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)松閘。切斷線圈電(dian)(dian)(dian)源后(hou)，制(zhi)(zhi)(zhi)(zhi)動(dong)桿在彈簧(huang)作(zuo)(zuo)用(yong)下使(shi)(shi)(shi)(shi)銜(xian)(xian)鐵(tie)脫離磁(ci)(ci)(ci)軛，而(er)制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)則將(jiang)機構剎住。制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)的(de)(de)(de)主要(yao)技術參數是(shi)行程、一定行程下的(de)(de)(de)電(dian)(dian)(dian)磁(ci)(ci)(ci)吸(xi)力(li)、操(cao)作(zuo)(zuo)頻率和(he)(he)通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)持續(xu)率。操(cao)作(zuo)(zuo)頻率是(shi)指每(mei)(mei)小時(shi)(shi)操(cao)作(zuo)(zuo)的(de)(de)(de)次數;通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)持續(xu)率是(shi)指每(mei)(mei)次通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)時(shi)(shi)間與(yu)(yu)每(mei)(mei)次通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)及不通(tong)(tong)(tong)(tong)電(dian)(dian)(dian)時(shi)(shi)間之和(he)(he)的(de)(de)(de)百(bai)分(fen)比。使(shi)(shi)(shi)(shi)用(yong)中，制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)與(yu)(yu)瓦式制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)相(xiang)(xiang)配合時(shi)(shi)用(yong)短行程類;與(yu)(yu)皮帶制(zhi)(zhi)(zhi)(zhi)動(dong)器(qi)相(xiang)(xiang)配合時(shi)(shi)用(yong)長行程類。制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)通(tong)(tong)(tong)(tong)過液壓(ya)(ya)方(fang)式將(jiang)電(dian)(dian)(dian)磁(ci)(ci)(ci)力(li)傳(chuan)遞給制(zhi)(zhi)(zhi)(zhi)動(dong)機構的(de)(de)(de)稱(cheng)液壓(ya)(ya)制(zhi)(zhi)(zhi)(zhi)動(dong)電(dian)(dian)(dian)磁(ci)(ci)(ci)鐵(tie)。

閥用電磁鐵

供遠距(ju)離(li)操作各種液(ye)壓(ya)(ya)、氣動(dong)(dong)系統閥(fa)(fa)門(men)的(de)(de)(de)(de)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)。常用(yong)(yong)(yong)于各種金屬切削(xue)機床(chuang)中(zhong)。閥(fa)(fa)用(yong)(yong)(yong)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)不(bu)設復位(wei)裝置，而由(you)(you)閥(fa)(fa)體中(zhong)的(de)(de)(de)(de)彈簧(huang)使(shi)之復位(wei)。當電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)的(de)(de)(de)(de)勵(li)磁(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)通過電(dian)流(liu)時，電(dian)磁(ci)(ci)(ci)(ci)(ci)吸力(li)即克服彈簧(huang)阻力(li)，使(shi)閥(fa)(fa)體的(de)(de)(de)(de)推桿(gan)(gan)移(yi)動(dong)(dong)，將閥(fa)(fa)門(men)開啟;當勵(li)磁(ci)(ci)(ci)(ci)(ci)繞(rao)組(zu)斷電(dian)后，在復位(wei)彈簧(huang)作用(yong)(yong)(yong)下，閥(fa)(fa)體推桿(gan)(gan)便推動(dong)(dong)銜鐵(tie)，使(shi)其(qi)移(yi)動(dong)(dong)額定行程處(chu)，閥(fa)(fa)門(men)關閉。閥(fa)(fa)用(yong)(yong)(yong)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)分為濕(shi)式和干(gan)式兩種。濕(shi)式閥(fa)(fa)用(yong)(yong)(yong)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)的(de)(de)(de)(de)銜鐵(tie)在液(ye)壓(ya)(ya)油中(zhong)工作，由(you)(you)于油的(de)(de)(de)(de)冷卻作用(yong)(yong)(yong)，使(shi)其(qi)與具有相同吸力(li)的(de)(de)(de)(de)電(dian)磁(ci)(ci)(ci)(ci)(ci)鐵(tie)相比，有較(jiao)小的(de)(de)(de)(de)尺寸(cun)。

電磁鐵的應用

門(men)禁：為什么(me)門(men)禁可(ke)以(yi)在沒刷(shua)卡(ka)時把門(men)牢牢的“抓住”？原(yuan)來(lai)單元門(men)是由鋼材(cai)料(liao)做(zuo)成的，那(nei)個(ge)金屬(shu)體在通電時可(ke)以(yi)產生(sheng)強大的磁場(chang)，產生(sheng)的磁力能把門(men)牢牢的吸住，而刷(shua)卡(ka)的瞬(shun)間，切斷電流，金屬(shu)體失去磁性，我們(men)就可(ke)以(yi)打(da)開(kai)門(men)了。那(nei)個(ge)金屬(shu)體其實(shi)是一塊電磁鐵。

電磁起重(zhong)機(ji)(ji)：最直接(jie)的應用之一(yi)是電磁起重(zhong)機(ji)(ji)。電磁鐵(tie)安(an)裝在吊(diao)(diao)車上，通電后(hou)吸起大量鋼鐵(tie)，移動(dong)到另一(yi)個位置后(hou)切斷(duan)電流，鋼鐵(tie)被放下，免(mian)去了打捆的麻煩。大型電磁起重(zhong)機(ji)(ji)一(yi)次可以(yi)吊(diao)(diao)起幾噸鋼材。

在電動機、發電機、電鈴和電磁(ci)(ci)繼電器里也(ye)用到電磁(ci)(ci)鐵。全(quan)自動洗衣機的(de)進水(shui)、排水(shui)閥(fa)(fa)門，衛生間里感應式沖水(shui)器的(de)閥(fa)(fa)門，也(ye)都(dou)是由(you)電磁(ci)(ci)鐵控制(zhi)的(de)。

電(dian)磁(ci)(ci)鐵的另一個應用(yong)是產生強磁(ci)(ci)場。現代技術中很(hen)多地方需(xu)要的強磁(ci)(ci)場都(dou)由電(dian)磁(ci)(ci)鐵提供，如大型電(dian)動機、發(fa)電(dian)機、磁(ci)(ci)療設備等。